getting to the desktop

[Glenn Ervin]

    Hi,
I don't know if this only happens on the live CD, but I am running Ubuntu 
10.04 on a laptop with a gig of ram, it was made to run Vista.
I am using Orca too.
Anyway, when I do control + alt + tab and get to the top panel, looking for 
the icon for my wireless, and I arrow around, I get stuck in the menus of 
system, accessories, and places.
Sometimes I manage to get back to the top panel, from the menus, but all I 
can do is tab to where it says "new appointment" and back to help and one 
that just says"menu".

The command control + alt + D does not get me back to the desktop.  I have 
tried using the mouse to get back there, but even though it reads desktop 
icons, the active curser is still stuck in the top panel.
Is there a list of keyboard commands to help with such things?
Thanks.
Glenn