Currently getting BSOD crashes on 4 of 20 boxes with NIS installed. Evidently this is a known issue related to a particular Windows Update according to chat support - I am just waiting for the fix. Am really surprised that Google searches turn up almost nothing for this error - is this not happening to a lot of NIS users?
The only info I could find was at http://answers.microsoft.com/en-us/windows/forum/windows_7-performance/bsod-the-bugcheck-was-0x000000df/274ea2f2-9595-40f9-8588-8fa675b9abc1 where the conclusion was eventually reached that this was Norton related, so I chatted with Norton Support. Sharing so it will hopefully help to point people here as well.