Periodically my mounts on my Redhat system to another system go stale
and display question marks and the mount point flashes RED. In one
case the mount is from and SGI Irix 6.5.23 system and in another it is
from a Redhat Enterprise Linux AS 4 Update 4 system.

The display from an "ls -al" is like the below. I've provided a
normal line
appearing above the one in question.

drwxrwxrwx 3 root root 4096 May 10 2007 data
?--------- ? ? ? ? ?
maps (flashing red)

My fstab on the "flashing red system" has:

eagle:/maps /maps nfs defaults 0 0

Any ideas?