[orca-list] Moving between frames in web pages with Orca and Firefox

[Ollie <mallard ilgerone net>]

Hello list,
Yesterday I tried for the first time to do some shopping on the 
website of the supermarket I usually shop from in Windows, with NVDA.

The website has a number of frames, which I usually handle by 
pressing M and Shift+M.
I found no keybinding in Orca or FF (I'm using Vinux 3.2= to jump 
from one frame to another.
This is essential for that kind of site.
Is there anything I've missed? How can I move between frames with Orca and FF?

Thanks in advance for any help you can provide.
Ciao,
Ollie