Cache Troubleshooting (Gallery Related?)

I have a strange caching issue that might be related to Gallery. I’m now running the following (quite vanilla at the moment):

Revo 2.0 PL
PHP 5.2.10
Apache 2.2.3
MySLQ 5.0.77
CentOS 5.5

About a week and a half ago (while still running Revo RC3), I noticed that the console no longer gave any output when clearing the cache. Resource caching is being successfully cleared, however. I’ve upgraded to PL and have the same issues.

This behavior might correspond with the installation of Gallery and the creation of a couple of large galleries (206 images, 219 MB total, split up into about 8 galleries, but all sitting in a 2010/07 folder).

Right now the Gallery plugin no longer seems to remember any image caches (caches for galleries are being created each time someone visits a gallery, however, and the cache/phpthumb folder keeps growing and growing). I haven’t changed the default settings for Gallery. Have tried to modify Gallery snippet calls with and without "!" etc. and I get the same behavior.

My plan is to uninstall Gallery and then manually clear all the cache files to see if that fixes the issues. Then I will start playing with Gallery, recreate my galleries while tweaking the Gallery or phpthumb settings, and hopefully my Galleries work quickly again (like they did at first). I’m not 100% sure that Gallery is causing the console problem or I would post this in the Gallery support forum.

All cache settings are currently set at default values (although, this install of Revo was successfully using some cache expirations right before the console and other caching problems started).

I have a couple of questions:

Does anyone have tips for cache troubleshooting?

Is there a recommended procedure to manually clear out the cache for Revo? (Phpthumb caches?)