I'm having the same problem. Here's what free says:
[jade@intranet /tmp]$ free
total used free shared buffers cached
Mem: 127848 121164 6684 49288 3448 26440
-/+ buffers/cache: 91276 36572
Swap: 409616 14900 394716
I'll follow your advice, Don, but it looks like this problem is fairly pervasive if it's not just me... Brian, how much memory and swap do you have? The intranet should be working, right?