Random hangs and reboots with 1970 and XPsp2

I am running XPSP2 with the relevant security updates under build 1970.

Well, I should say "I wish I was running". But let's start from the beginning. I have used Parallels since the very first beta that was published and overall had very good success with - and continued to update to newer version as they came out.

Ever since build 1940 (or something like that - don't have the .dmg anymore) I have had tons of problems with random reboots which after a while tend to destroy the filesystem to a degree that Windows no longer can successfully boot - usually I get the "hangs when loading Mup.sys when in safe mode" style of problems. Recovery console can't fix things, the only thing that tends to help from here is a reinstall. This has been so bad that I now have a fully patched image ready and keep most of my data (as far as the software allows) on a different drive image in order to expedite the reinstallation / new setup.

Needless to say, this is highly frustrating. I have tried everything I've seen as hints in the forum. Turned of all non-vital devices (my configuration no longer has sound or USB, just the two HDDs, network, shared folder and a nice video mode). I tried both shared and bridged network. I tried starting without network. I cannot tell you what triggers the corruption, but once the first "random crash" happens it degrades quickly and reliably ends up at the destroyed filesystem.

Any ideas what is causing this and how to fix it?

Thanks

/D