After browsing the forum, I found this post: http://www.geekstogo...und-t16988.html
which was very similar to my problem (only I never lost the tab, it was simply grey and I was unable to browse or change the wall paper). The first solution was an inactive link, I used the second download suggested, restarted my comp, and that problem is gone! (thanks!). I can now change the wall paper.
The trouble that remains: I get an error on start up. It's c:\windows\ftamobunitobabu.dll that's missing. Should I go to regedit and delete or try to retsore?!