Which version or CWP are you using? I'm using
CWP version: 0.9.8.398
and it's gotten much better. Seems to stem from a leaky version of nss that causes curl calls to query none existent files the results of those queries are stored in dentry cache IIRC.
try looking at slabtop from the command line. if the dentry cache is HUGE this is your problem. Long term solution is to make sure your yums are all up to date and you're running the most current version of CWP. Short term solution is:
service httpd stop
service mysqld stop
sync && echo 2 > /proc/sys/vm/drop_caches
service mysqld start
service httpd start
This will drop your dentry cache but you want to make sure no services are writing to disk when you run it because they'll stop mid write. Also just a warning, it can take a sec for it to run.