I've run into a problem where after updating my clients from 11 to 11.1 I'm now getting a BAD_POOL_HEADER bluescreen. This seems to be happening mostly on HP Laptop (6530b) devices, however I do have a report of a Dell (E5410) having the same problem. I've done a bit of a search and saw something about the HP Mobile Data Protection Sensor driver having problems with the zesdac filter (see ZCM Agent and HP Mobile Data Protection Sensor), however this was apparently fixed in Cumulative Update 1. I did a manual check of these registry keys to double check and all seems fine.

Being a BAD_POOL_HEADER BSOD is usually driver related, I have to think it's something to do with the Endpoint Security Module (which we dont use - but is installed on clients regardless). Has anyone had anything similar? or any suggestions where to go looking? This happens both on XPSP3 and W7SP1 machines.