Disk Cache Not Overwriting Itself

I think this is a cross-platform issue, though it seems to depend a lot on how the disks are formatted and where the cache is stored. I've seen it reported for Macs a couple of times as well, but perhaps not as often, though there are other issues on OS X. There's no clear pattern to it, as it seems totally random, so it would be hard to advise on anything. At some point while you work AE will simply decide to calculate a new session key/ hash value for the cache sequence and then nothing works anymore. Sometimes messing with the hardware acceleration options and graphics driver settings improves things, as somehow too agressive processing seems to figure in (the way I figure it frames being calculated faster than can be cached and then being ditched, breaking the cache) and of course on a similar note multiframe rendering may also play a role. Turning off the latter for a more conservative and slower AE rendering might at least lower the stress on the cache folder. At any rate, you have to experiment and keep observing what works best for you. You may not be able to totalyl avoid it, but perhaps you can get longer undisturbed work time out of it.

Mylenium

That's a known issue/ bug. Somehow AE loses track/ dissociates cache files after they exceed a certain number of chace files. It should be fixed one of these days in an update. For the time being keep an eye on your folder directly or by using one of those simple freeware/ shareware monitoring tools that can generate sounds and messages. You could also create a conditional task in your Windows scheduler to regularly delete the files automatically, though being outside the AE loop it might remove too much and cause more headaches.

Mylenium