The disk caching in Mozilla (at least in versions 0.9.2 - 0.9.7) is unreliable in my experience.
On a Linux box (RedHat v7.2 /w 2.4.1x kernel) I download the SRPMS package from Mozilla's FTP site, then build and install the binaries. When I set a disk cache limit in Preferences I find that Moz slowly builds up that much data in the cache. Then the amount of data in the cache plummets and never regains the amount of data specified for caching. New objects are cached (you can tell by the timestamps on the cache objects) but the total amount of data never again exceeds ~4MB. If I go into Preferences and clear the disk cache, then erase the remaining _CACHE_* files from the cache directory, then all is well - temporarily. The amount of data builds back up to the size I specified, then the problem repeats itself. Once again the amount of data cached drops, never to regain the specified maximum. I've tried maximums of 16MB, 32MB and even 64MB. Thinking the problem might be some sort of boundry condition, I've tried odd (non power of 2) maximums. No difference in behavior. Has anyone else seen this? Thanks.
