LR3 hangs making 1:1 previews

[Victor Glass]

System: Mac Pro, 2.8 GHz Quad-Core Intel Xeon, 24 GB ram, set to 64 bits.
Lightroom (3.4.1) library and catalog on dedicated 2T internal HD.
Adobe Camera Raw cache on dedicated 160 GB internal HD, set to 80 GB.
Also PS5 is installed.

Problem: rendering 1:1 previews, even on a small (100) number of files, results in the spinning beach ball after any where from 30 to 60 are rendered.
There are files in the ACR cache, a number more than were rendered. This happens everytime I try to render 1:1 previews, whether during import or after import.
During import all files are imported and then the rendering gets hung.

Any help would be appreciated. The only thing I can think of is reinstalling LR. I've tried optimizing the catalog, verifying the Hard Disks, and defining the ACR cache on another disk.
Also does anyone know of a debugger that will show where the hang is occuring on the application and system levels?

[digitaldog]

The only thing I can think of is reinstalling LR. I've tried optimizing the catalog, verifying the Hard Disks, and defining the ACR cache on another disk.
Also does anyone know of a debugger that will show where the hang is occuring on the application and system levels?

So you deleted the ACR cache?

As for a debugger, you can try Console.

[francois]

So you deleted the ACR cache?

As for a debugger, you can try Console.

…Activity Monitor can also help.

I would try to create another user account, log in then create a new Lightroom catalog and see if the the issue is still present.