Welcome to the club. I have had the same problem and called Symantec support twice about it and they have never returned my calls.
I'll tell you what I've found out through my own research to try and find out some info:
1. Setting up a new CPS destination folder on a different drive (but same admin server) doesn't fix it
2. Setting up a new CPS admin server w/ a new destination folder on that server does fix it.
3. Looking in the log files for CPS I've noticed a lot off communication errors (orphaned connections etc)
4. doing a complete uninstall/reinstall fixes it temporarily...the problem comes back though.
The hard drive space on my CPS server is 1.8TB and is only half full.
I'll let you know what I find out if Symantec support will ever call me back!