Comment 33 for bug 88815

A couple of things/differences I noted whilst reading through your logs:
- The Xorg.0.log from Herd5 mentions it can't initialize the GLX extensions, since it is using the Nvidia libglx.so
Might this be the cause?
- In the Xorg.0.log from Herd5 AIGLX is disabled (since it can't load the GLX module)
- The Xorg.0.log from Herd5 mentions it loads a vm86 module (libvm86.so), which isn't loaded in the Herd4 log.

It might be good to try to keep the config the same, so the comparison is fair (though the stock config might be different).