OK for any other readers that might be having glitches or drop-outs using Vista OS here are some suggested cures from trawling the Web and talking to others. I have tried them all and none work for me.

1. Disable wired and wireless connections

2. Disable the enhancement in the Control panel-> Sound-> Speaker Properties->Enhancements->Disable all Enhancements.

3. In Media Player, click the down arrow under Now Playing and go to Enhancements. Click on Crossfading and Auto Volume Leveling. At the bottom of the Media Player, you should see that Crossfading and Auto Volume Leveling adjustments are showing. Make sure that Crossfading is off and Auto Volume Leveling is off.

4. In windows Media Player, hit ALT and go to TOOLS and the OPTIONS. Go to the Performance tab and under Network Buffering choose Buffer and change it to 1 second of content.

5. Set power management to High Performance.

6. Disable internal sound card completely.

I'm yet to update drivers on the motherboard (waiting for Dell to help do this)

Good luck.

Incidentally Daniel Fuchs at RME in Germany is continuing to be very helpful in resolving this issue . Dell unfortunately are just too keen to point the finger at other peoples software/hardware. 

I'm currently having a big row with Dell .

They uploaded the updated drivers for the soundcard, but no better, and now they tell me the soundcard in my new Inspiron 6400 PC is not specified to cover the sampling frequencies I want (up to 192Khz). Apparently it only works over the range 40Hz to 15Khz!!!!

I have asked how it is then that it can play a CD at 44.1Khz. The Chap in India didn't know.

Once I mentioned that I am using an external sound card they were only too quick to blame that, so they can dismiss my problems.

I have now asked to speak to someone who can understand my problem and can sort it out. Nobody has yet suggested upgrading the motherboard drivers.

OK Peter, I just needed a bit of direction.
I'm on the case tomorrow

Off to bed now - well pleased with Engine #3

My PC rebooted today once and that was when I was playing with the sample settings in the FirFace configuration menu with XX still playing. Everytime you change something on the fireface or XX settings then do restart XX to prevent that the fireface drivers get confused and trigger a blue/black screen and a reboot...

That makes a lot of sense, will remember to do that.

128 samples and all works well onder Vista and XX #3 (single, double and upsampling). No skipping here....

Lucky man

Do you use the latest fireface software driver and also the latest hardware driver (updating the fireface itself)?

Yep I use the self same software and drivers you posted earlier.

Hmm ... Chris ... From theory that is possible, because of my earlier expression (somewhere) that after this timeout it shouldn't present an error. So ... as long as it does while I don't understand why ... it could cause anything. I myself never experienced a reboot, but I think it just can.
Don't try to find the cause of this for now, and just blame me. 

The computer called it a blue screen event

About the glitches ... you know my opinion about that ... just take your time to get a grasp of that somehow.

Yes I'm convinced its not XX  . I was playing with media player at high sampling rates and it did similar (not quite as often). I think Dell will be getting a call soon

One last glitch to report:
XX was making its way through a short playlist. When starting one track, the marker at the bottom was moving, but there was no sound (no bars moving in the Fireface mixer). I stopped the track and restarted and all was fine.

Update

Its early days but I think my preference is for #3 doubled .

Both the upsampling and doubling work fine, showing 88.2 on my TacT.

Still getting some glitches/dropouts particularly at high sampling rates. Beginning to think this is a problem with Vista. I will continue to investigate.

Twice when XX timed out, it rebooted my computer - first time any of the engines have done this.

Just downloaded the software 8a again and now engine #3 is working 

F.....g computers

Engine #1 and #2 playing OK but nothing from engine #3. The track indicator at the bottom is not moving, but I have no error messages at all.

Have tried putting ticks in 'double' and 'upsample' but still no sound.

Hi guys

I have the wav files stored both on the C: drive and some on a USB flash drive. Same drop outs on each.

I do have difficulty finding the latest drivers (where to look) and also in knowing which of all my listed devices is the motherboard - nothing on the device manager is actually called a motherboard!

The drop-outs get worse as I increase the sample rate from 44.1. At 44.1 they are pretty rare, at 96 they are pretty common, and at 192 its almost unlistenable. This is a problem, as sound quality is improving with each increase in frequency. Incidentally my Tact is picking up the right signal all the way to 192. 

What about setting XX priority higher how do i do this?

Sorry to be such a nuisance.

Thanks Chris

Thanks Bert

I'm using the same Fireface 400 drivers and firmware as you, so will leave well alone there.

It sounds like setting the XX priorities higher might help, but have used search and help pages, and cant see how to do this? Any guidance?

(I have not bothered registering all the new software on my PC as I wont be using it on the internet much, but I keep getting pop-ups urging me to do it, so perhaps the PC is putting some of its efforts into trying to do that in the background)

PS
Sold my Counterpoint CDP and DAC yesterday evening so the computer jukebox is in the front line.

Oh dear, was hoping for a quick fix

Have recorded WAV files of many tracks on 2 PCs and all have these hiccups so convinced it's not the the raw data - also these ran perfectly on my XP laptop.

What drivers have you got in you Fireface 400?

Note to self  "dont panic and work through it all again slowly" 

Comforting to know I am not alone (this pioneering stuff eh!)

I think Bert also has a Dell Inspiron so hopefully he will pop up with a solution.

Thanks again
Chris

With both engine 1 and 2 there are a fair number of drop outs (more as I increase the sampling rate).

... just as that I wouldn't blame XX for this (but actually I can't tell ... about the first quote I can though, so I assume this is about the same problem).

If I must guess something : motherboard drivers, or very theoretically the Fireface drivers -> 1 %.
Since I don't like to experiment with Fireface drivers I don't use your version yet, but below you find the drivers which I use without problems.

If that doesn't help you should update all of your motherboard's drivers. And for those I can't help you ... (not experienced with that). So be careful.

Emmmmmmmm  was rather hoping it was XX. Now I have to find a cure myself

The laptop is a brand new Dell Inspiron, can it already have outdated motherboard drivers? The drop outs are sometimes when the PC is not being touched, but other times if I am doing something else on it, it happens.

I have turned the sound effects off on the PC, is there anything else I should stop running?

Will try changing the Fireface drivers to the ones you use and let you know what happens

Wow that opens up another big area for experiment (16/24 bit and change of sampling up to 192!)

There is a definite improvement for me as I increase the sampling rate I can see on my Tact that 192 is making it right through. Not sure if I should be running at 16 or 24 bit?

With both engine 1 and 2 there are a fair number of drop outs (more as I increase the sampling rate). I have got the buffer set at a maximum 1024 but this does not fully cure it. I guess engine 3 will sort it out

Sorry Peter, but I'm a bit confused now (again).

Somehow I formed my own impression that my CDs would need to be copied and assembled in their own library on the PC (hard drives), with album sleeves and track listings attached. XX would then delve into this library to take out whatever is selected and put it into a playlist. It's the setting up of this library that I was asking about.

From your reply I think you are suggesting that XX will be able to offer the entire package including structured library, and storage of album sleeves, track listings etc. and that for the time being anything can be stored in Windows folders and transferred over eventually.

Have I misunderstood?

Thanks Chris