Tried to use nfs... played with it... wouldn't mount a solaris boxen, so therefor i thought ah hah it must be a nfs issue... Tried to use samba ... played with it... wouldn't mount to another redhat 6.x boxen same problem exibited on both boxen (server and client). Tried to unmount two filesystems same problem....
We need more information such as what the exact line you are using to mount the servers, how the servers are set up, etc. You may want to consult tech support to help resolve these issues.