If you happen to be trying to open files/programs across an NFS shared drive, check the value in RET for 272. This error code (EBUSY -- Device/File busy) will be returned by the operating system should the 'lockd' background daemon not be installed and active on the host Unix server.
This can happen if you only install/activate the NFS server modules and not the standalone 'lockd' daemon which is part of the NFS-Utils installation.
On Unix/Linux you should be able to check to see if the lock daemon is running by issuing a command similar to this:
ps -leaf | grep lockd