No Internet Connectivity after NAV 09 Update

I've seen users with variations of this problem before, but not quite for my same situation:  I downloaded NAV 2009 this week to replace NAV08 that I was running (machine is using XP Home SP3).  At first, no problems, and I liked the new interface with NAV09.  But...

Wednesday 2/4 after receiving live updated definitions, all internet connectivity ceased.  No IE, Firefox or Outlook functionality.  Wireless connection shows good via 2Wire router, but all internet functionality is dead in the water.

I can't even connect to Symantec server for further updates or help options.

I'm currently on my office machine, so I'll have to take any solutions home to try them, if there's a basic procedure I can try to toubleshoot this.  Failing that, I'll have to uninstall.  Thanks for any help and suggestions!