Some Computer Help?

Okay, I know, me asking for computer help, right? But it's true.

Here's my problem: my work computer, a Motion Computing tablet PC, has suddenly developed an inability to perform simple networking functions. Oh, it LOOKS as though the various network hardware is connecting with my various routers and switches, but within about five minutes of start-up, suddenly I get nothing. Try to load a page (in any browser) and I get nothing. Sometimes, worse than nothing, I get just the homepage, so long as I started the browser promptly. Click on a link, and I get a moment of something trying to do something, but then just the same page, making me wonder if I actually clicked the link or just hallucinated it.

Here's the kicker: When I open PuTTY and try to connect to one of my *NIX accounts, I get an error message regarding the network buffer being full.

Spyware? Virus? Other? Anyone got any good ideas?