Is it possible you are running out of file descriptors?
These are where the FD max is set (box-wide)
/proc/sys/fs/inode_max (should be 3-4x file_max)
There was a bug in rhnd causing FD leakage, but I think that was pre 7.2. You may want to shut it down if it's running.
I'll take a look at it, but I dont think we have a problem there...