Windows 2008 Server cannot access any network share

I run a Windows 2008 server with SP2. This server acts as a desktop alone. Recently, I switched between two networks (corporate and other) using this system. Ever since, I am unable to access any network share on the original network from where I installed and configured the desktop. The message I get is "Network path was not found". Note that I am able to access the internet and my corporate mail server.

I am told this is a Vista and Windows 2008 specific problem and I have done everything I could think of:
a) Deleted the second network settings from the desktop
b) Installed a patch from MS that supposed took care of this problem (with MS clearly saying they had not tested this enough)
c) The SP2 install was after the problem occurred and I went ahead with it in the hope that SP2 may have something that would fix this

Some additional details:

a) A system admin can log into this system from a remote terminal
b) I cannot get into my own system using the hidden share C$ – for instance \mymachine\C$ gives me the same message as above – Network path not found
c) I can log into my system remotely using mstsc
d) I cannot create shares on this system – as an extension network printers are not detected

I have an update for you: The error message is as follows –

****Network Error****

Windows cannot access \\network_share

Check the spelling of the name. Otherwise there might a problem with your network. To try to identify and resolve network problems, click Diagnose.

Clicking Diagnose gives Error Code: 0x80070035
The network path was not found.

Any help will be appreciated

Thanks