I found the culprit causing the lockup in 7057 x86. It was my screensaver, DreamAquarium.scr. Great screensaver but it appears to not function well in build 7057.
I uninstalled DreamAquarium, now let's see if lockups go away.
I am also getting this in the Event Log for build 7057.
Event 7045 Service Control Manager
A service was installed in the system.
Service Name: INSTB32
Service File Name: C:\WINDOWS\TEMP\INSTB32.SYS
Service Type: kernel mode driver
Service Start Type: demand start
It started logging Saturday 3/14/2009 and re-occurs at random times. I have searched the internet but no real information is conclusive. The above file does not exist on my system. Avira and Defender did not detect it as harmful, if it ever was there. The only thing I installed just prior to when the error started was the new Adobe Reader v9.1. FYI.