Can't view sharedDocs - Missing "Entire Network" icon

I noticed on a XPSP2 Pro machine in a workgroup of XPSP2 Pro machines the
"Entire Network" icon, under "My Network Places" is missing. I
am not quite sure what had been done to the machine prior to my being asked
to troubleshoot it. I had noticed the following prior to noticing the
missing icon:

With the exception of the machine in question, machines in the workgroup can:
1. see one another.
2. have access to one another's SharedDocs folder.
3. All machines in the workgroup can view the content of the SharedDocs
folder on the problem machine.

Problem machine:
1. can ping other machines in the workgroup.
2. cannot net use to other machines in the workgroup.
3. no machines are listed with the net view command.
4. nbtstat enumerates machines in the workgroup.
5. all settings appear to be correct (did not run gpedit).
6. "Entire Network" icon is missing in Windows Explorer on problem machine.

What would be the most likely reason for the missing icon, and inability to
successfully connect via net use?

Great thanks in advance,
--
MadRat