I can confirm this as well. I'm running xp guests on two mbp (both i7 and ssd) and since updating to v6.11992 I have been seeing more or less sporadic registry and filesystem corruption on both machines causing a variety of unrecoverable failures forcing me to either reinstall xp or restore from a backup. The problem might be related to parallels tools for windows, which had been causing problems before already (eg. prl_boot failing). I also didn't see any problems at all using ubuntu guests with 11992. I have been going back to 11828 which appears to work pretty stable. Since lots of users do not seem to have issues with 11992 I would be curious what we have in common. Could it be related host cpu type and/or vm image residing on ssd?