Sudden Extreme Memory Spikes

I've posted this same problem in File Framework, but I figured since they are connected I should probably post this here too:

I'm using Bitcache with File Framework to host a file database. It works great, except for one extreme problem: Every time someone uploads even a TEENY TINY file the system memory appears to jump a couple hundred megs of memory. You can see my statistics here:

http://www.runicgamesfansite.com/mrtg/

The bottom graph is the system's memory, and most of the sudden 200-300 meg spikes appear to correlate to when people have uploaded a file. I'm running the latest dev versions of file framework and bitcache, but still there is no change. I saw someone say they managed to fix what appears to be the same problem several months ago, but as far as I can tell all they did was change the order of their installation.

What should I do?