I've recently had a sudden problem with application not loading up after execution where even control panel features would not load up.  I've did a manual scan with safe mode on (purging a few ad-ware in the process), rebooting and coming up with the same problem, I performed a system restore before the problem occurs allowing me to be able to run the operating system normally.  
After a day of it working, I've encountered the same problem again.  Something I've noticed is that it occurred several minutes after Bitdefender has performed its update.  Going on a hunch, I've disabled [service: Bitdefender update and virus shield] and [start-up BDagent].  A reboot reveals that the operating system performed as normal and seems Bitdefender was the cause.  
Is there an explanation to this phenomenon?