I had similar issue with other folks posted on this Forum machine experienced BSOD issue on some of my machines with SEP 11.0 installed. My issues started to happen when I started to deploy device control to manage the removable storage.
I have one policy that withdraw Application and Device Control, which means there is no device control to cleints, i call it device enable group. I also multiple groups, either disable certain or disable all removable storage devices.
when I moved the client to the device disable group to disable removalbe storage devices, my client contacted helpdesk reporting machine blue screen and reboot looping at the next reboot time.
In my "blocked devices", I blocked all the removable devices. a long list including USB, CD/DVD. Floppy, etc and in my "devices excluded from blocking" I allow different type of "Human Interface Devices", and IDE Disk, Device name: IDE DISK, Identification: IDE*
My understanding is SEP 11.0 code to be able recognize which drive is the OS boot drive, with my devices exclusion configuration, I found this might not be true, by checking the logs on the blue screen machine, I found machine hard disk was blocked for OS access, I updated my devices exlusion policy to exclude "IDE\DISK*", on the blue screen machine F8 to boot into option and choose safe mode with network, once logon, update the SEP policy, then reboot the machine back into normally mode and machine never experienced blue screeen since then. The blue screen does not happen to all the machines, it could be SEP 11.0 does not work as designe on certain hard disks, I have seen the issue on some WD and Sumsung drives. This fix might not fix your issue, but you at least to have some clue where to start to troubleshoot this type of issues.
Also I saw couple of posting that people stated it took more than 3 months for Symantec to perform dump analysis and still no result, I do not think this is acceptable SLA, I hope Symantec really can improve their post sell services.