Hmmm...
Only happening in Firefox. Opera and IE6 / IE7 are not having this problem.
All better - for now. Blew away all Google-related cookies and it is no longer occurring, though I did read a few blog posts saying it is happening to others using Firefox 2.0.0.12 & 13. seems to occur whenever you search in Google and are also signed in to another Google service on another tab, like Gmail or G-Cal. Cookie fix has worked for most but I did see a few where it returned later.
Grrrr....
Jim