Jim, I am more than willing to accept that it is not an MC issue (or an MC-only issue), matter of fact that is why I have tried both WinXP and Win2K.
As far as another machine, my main MC/media machine (the one with the behavior in question) uses LOCAL drives, to try using another machine requires using network drives and thus adds another variable.
I have tried your other suggestions in recent past while trying to isolate this issue, but like removing A/V software I am willing to re-explore these possibilities.
Disk access is normal in Windows and other programs which leads me to believe there is no problem there.
I have run MemTest and SeaTools which both report no errors or isues.
I avoid plugins other than Sleeptimer and Library Server, and have tested with LS deactivated and Sleep Timer removed. I have also tried a fresh, clean library (no clones from older libraries or such).
Unless there is a Dual-Core CPU accessing issue, an Asus/NVidia chipset/driver issue, or a drive polling issue caused by library drives being off-line, I am at a loss at this point.
I get occasional issues like this with my WD WorldBook NAS device. (Gigabit ethernet support on that device is a A LIE! A LIE I tells ya!) I have the same issue if I just double click the device in explorer.
I am not using NAS or other network storage, only local drives.