This is definitely a weird interaction, as neither the screensaver nor its components actually run on the CentOS machine. I have not checked whether any other activities in a vnc session cause similar behaviour.
Where does the screensaver's data files (eg where are the quotes stored) live? If on the CentOS machine, then it is simply that the screensaver is making lots of NFS I/O operations.
On the filer. But this retrieval script runs on the RHEL3 box(es).