cache doesn't cache

hi all,

i ran into a slightly odd problem. i'm using the following settings:

cache_dir aufs /mnt/cache/squid 900 16 256
cache_mem 600 MB
maximum_object_size_in_memory 2 MB
maximum_object_size 10 MB

that works fine except for one thing: the cache sizes don't change at all. the folder's size as 
well as the ram used by the squid process are like set in stone. no matter what i do they don't 
change at all. even after days and weeks their size remains the same. the cache folder is stuck at 
63mb and the squid process comsumes 59mb in total. no changes to these values at all.

what am i doing wrong?

thanks for any hints in advance!

--
R-A-C
Götz T. Fischer CertIT&Comp
+49(0)7225/98 98 79
[email protected]
r-a-c.de