- GetWork Failed: Server not responding, Retrying in 5 minutes

I've been running the software in 3 separate solaris box for quite a 
bit now.

They were fine until lately (3 weeks now I realized) that only one 
machine keep running but the 2 are not. And the ff. is message that 
keeps repeating. 

Getting work
- Connecting to assignment server (IP = 171.64.122.87)
- Requesting work server address 
- Connecting to server (IP = 171.64.122.100)
- Connection established
- Requesting work: Network Recv Timeout
- GetWork Failed: Server not responding, Retrying in 5 minutes

I already tried to delete everything and untar the sol...*.tar file 
to install it again. But still same messages.
Any clue? Thanks.