I have been using Ubuntu for 12 months and now have 8.10 which has been working perfectly until a couple of days ago when Firefox suddenly started to hide the top and bottom Gnome Panels. No other package does this including Sea Monkey. Selecting Edit Preferences (twice - it doesn't work the first time) suddenly restores the panels without making any changes to the preferences but on selecting another package and returning to Firefox the problem comes back. I have used Synaptic to re-install Firefox to no avail. There does not appear to be a setting in Firefox to fix this. Any ideas? I will continue to use Sea Monkey unless someone can help.

Thanks

What happens if you push F11 when in Firefox? Sounds like it's gone in to full screen mode.