To explain further, I have had this exact same error on TWO different computers, one of them completely new, while running the same combination of programs/drivers. They are both Stop code 3b with Parameter 1 the same, 0x00000000C0000005 (though Parameter 2 and 3 are different for each time the BSOD comes up). The two computers have different graphics drivers, so I believe graphics drivers can be ruled out as the problem (one is a AMD Radeon 6750M, the other is an Intel HD Graphics 4000). The graphics drivers are also updated. They are both running Windows 7, one is a Lenovo ThinkPad x1 Carbon, the other is a Macbook Pro running Bootcamp (I blamed bootcamp for the problem, which is why I got the new computer, but it seems that it is not the problem).
In both cases, I am running a 30" external monitor via a DVI-D to Displayport adapter, made by Accell (with additional USB powering). I believe this may be the problem, because after several days not using the monitor I did not have the crash. This is not conclusive though, because it normally only crashes every 2-5 days, but I think it may be a good place for a knowledgeable person to start. However, I used the computer for many months without any crashes with this external monitor, and it has only been crashing in the last month.
I am also running a Logitech external trackball mouse and have a somewhat new Brother printer and it's associated drivers. I have Nod32 ESET antivirus, updated to the most recent version. I'm also using a program that uses a PostGreSQL database, and am running several applications at a time (not graphics intensive but I believe it does use up a fair amount of resources). For the most part, the crash has only happened after a couple hours of use. I have had all of these things installed and running on both computers when they crashed.
According to BlueScreenView, on both computers the error is caused by driver win32k.sys, caused by address win32k.sys+7d010. The crash address is ntoskrnl.exe+7efc0.
My plan is to keep using the computer(s) without the external monitor, and see if they ever crash. If the monitor is the cause, I would hope for some solution that would allow me to use the monitor (I'd be willing to buy a new adapter if it might make a difference).