This WinPcap driver still exists and is active, in your latest crash dump just posted.
Perhaps the software that you installed that installed it too, re-installed it.
Check about that again.
0: kd> lmvm WPRO_41_2001
start end module name
fffff800`034db000 fffff800`034e7000 WPRO_41_2001 (deferred)
Image path: \SystemRoot\system32\drivers\WPRO_41_2001.sys
Image name: WPRO_41_2001.sys
Timestamp: Mon Nov 07 16:04:48 2011 (4EB847F0)
Translations: 0000.04b0 0000.04e4 0409.04b0 0409.04e4
What I would do for now too is to remove a stick of RAM. Run the machine like that until you're confident that it is stable.
If it is, replace the RAM with the other stick and try again. See how that goes.
Maybe one of them will crash a lot and the other not. Basically, experiment doing real things that you normally would use the machine for.