Firefox/Thunderbird gone brown (Edgy)

[Ian Rose]

Kubuntu 6.10, Gnome never installed. The effect occurs for ALL users, 
and the same profile does NOT have the effect when used on what should 
be an identical vanilla Kubuntu install. Fresh profiles and 
purge-reinstalling Firefox and Thunderbird makes no difference.

Since the recent Thunderbird security update, both Firefox AND 
Thunderbird (but on one machine have gone all brownish and horrible. The 
select highlight on menus also leaves each entry on the menus 
permanently darker after you roll over it. Also some fonts (ONLY in 
Firefox and Thunderbird, and only recently, and only on the one machine) 
have now gone wrong, with thickened strokes on some letters.

Other Gnome-y apps (Gaim and Xchat) have also caught a partial dose of 
this - they've gone all brownish, but without the other effects.

This effect DID occur for me towards the end of Edgy testing, but I 
never chased it down, and when I fresh-installed Edgy release, 
everything was fine.

Anybody with any suggestions as how to resolve this problem?

-- 
Ian