Did you install the multi-tuner patch after installing XP SP3?
I presume you mean this - https://forum.team-mediaportal.com/...ner-issue-channel-scan-crash-windows-xp-6344/ in which case, the answer is yes.
I had a similar problem on my wifes client in the lounge room.
My fix was to stop windows shutting down USB on sleep in device manager.
I too have a Nova T 500 card in my server machine with no dramas. That one is awake all the time.
Thanks for the suggestion Russell, that might be worth a try.
If I go into Device Manager and view by connection, working backwards I can see both the Nova-T tuner and IR components under "USB Composite Device", which is under "USB Root Hub". I can go to the Properties for this Hub and under Power Management, untick the box which says "Allow the computer to turn off this device to save power", which obviously affects both parts of the Nova-T (tuner and IR) but I imagine the idle power usage is negligible, so if this works it seems like a good solution.
The problem hasn't actually re-occurred since I originally reported it, so it will be hard to tell if this has actually fixed it, but if the problem happens again I guess I'll know it hasn't