Problem changing active group

Hi guys, I'm a relative newbie in SL (having been offline for couple of months due to illness). Since i logged back in a couple of days ago, I've been unable to change my active group to a different group. I've just re-d/loaded the SL software & that hasnt helped. Clicking on 'Groups' in the screen menu or when right clicking on my av has no effect. Any thoughts will be appreciated.
Thanks in advance.
CK

Long ago, I saw something like this sporadically when SL was exceptionally b0rked, so if all else fails, I'd try this on a different sim (if that hasn't already been tried).

But, lasting already for a couple of days, I suspect something else is going on, and the "no effect" thing when clicking on something that should bring up the Groups tab of the chatterbox might be a clue. Does the chatterbox window even appear when you click the Communicate button? If not, then I suspect it's outside the visible area of the screen. In that case, the easiest solution if it works is to increase the resolution of the SL window (in Edit / Preferences / Graphics), or maybe to toggle between Run in Window and Full Screen modes. If that doesn't work, then there are some application settings files that can be removed (they get rebuilt the next time the program runs), but their location on the filesystem depends on which operating system is in use.

Now, if on the other hand the chatterbox is appearing, and just no Groups tab is available, I have simply no clue what could be going on there. I'd probably still try trashing those application settings files to see if it helps, but can't think why it should.

It WAS outside the visible area of the screen! Awesome- thanks so much for your help!