I have done some very extensive testing after having this problem. All leads back to Bitdefender 2012 installation.
I upgraded from 2011 after getting an offer to get a free 6 months for free. The install went without a hitch. No problems what so ever. I routinely put my system in standby mode when I'm not using it for a while during the day. The first time I resumed from standby it took much longer then usual but I didn't pay it too much attention. A couple of days later it went into standby without a hitch but would no,t resume at all. You could hear the system turn on ok but never completely came out of it....black screen. System appeared to be running but nothing on the monitor. So, after about 6-7 minutes I just hit the reset to restart it back up. Well from that point on the system wouldn't reboot entirely kept getting stuck on the welcome screen. If I let it set on the welcome screen for about 10 minutes it would eventually get to the desktop but it was still unusable. I must have rebooted it a dozen times to no avail. I got into safe mode and tried to restore it back to a previous point but it failed to restore. (I don't even know why I let system restore even run on my systems, it has only worked 1 out of 12 times anyhow)
Now thinking it may have been something else in the system I pulled out memtest ane seagate tools and ran them all as well as check disc. No problems found. So after about 3hrs. of work the system decided to boot and seemed to be running fine. I said ok I'm tierd and went on. About two days later after a non resume from standby the system would not boot again. This time it wasn't coming back. So I took a shot in the dark and cleated the CMOS and reset my parameters in the bios and still nothing. So at this point I decided to image the drive with True Image and save it on one of my backup disks to retrieve files at a later date. I pulled the Sata cable off the primary drives and backed all the data I had stored on my secondary drive to my backup disk and turned my secondary disk into my primary bootable disk. I then used True Image to restore the first image I had made after building the system. The system booted fine with no issues. I started going to Windows update and updating the system and putting all my software back in. The whole time putting the system in standby and coming out without a problem. I had everything installed except for Bitdefender 2012. The system was running fine. So at this point I was a little curious and stut it down and put the Sata cable from my primary drive back on to see if it would reboot now. No luck, it was dead just hanging at the welcome screen forever. So I just figured that maybe the registry was hosed or something with the file system after all I had at least 3 other AV programs on this system at one time or another. Every time I switched to what I thought was a better one at the time. After installing and uninstalling so many times maybe something was now causing problems. I switched the drive back and said what the *ell and preceded with getting my system up and running.
I installed Bitdefender 2012 and all went fine as it did before. Well at least until I put it into standby again. It took about 7 minutes to come out. I was not happy at this point. What ever was going on with the other os is now going on with this one and now I have the culprit. I switched the Sata cable back over to the drive that was giving me so much problems and tried to boot it. Of coarse it did not, so I got into safe mode and tried to uninstall Bitdefender 2012 through its own uninstall and it failed after three reboots. I tried Windows add and remove to get it off and it failed. I remembered that when I first got Bitdefender 2011 it also had problems with a slow boot time after an update that came out so I had to uninstall it and turn off automatic updates until they pulled that update off their servers. They gave me an uninstall tool and I found it and used it in safe mode. It worked just fine and after that the system booted up fine ane even came out of standby without issue. I got on Bitdefender tech chat and was told that 2011 will work with the new license key and keep my extra 6 months. I installed and at this point and time it is working fine coming out of standby as well.
I don't know what 2012 is doing either going into or coming out of standby, but until they get it fixed I'll be running 2011. I think I've done enough testing. It was suggested I run their diagnostic tool but it has to be run when the system is having an issue and when I asked them how I was supposed to run the tool when the system wouldn't boot that's when it was suggested to use 2011.
Thanks
Patrick