Forum display + Firefox 6 beta

Yesterday for some reason FF decided not to display Avast forum properly.
I have lost all the formatting, background GUI/template etc
I have updated to Beta 2 but still the same

Am using IE9 without problem

Have you reported the problem to Firefox ???
Remember you’re using a beta product.

One reason to stay with stable version update. What’s with the rush anyway?

What's with the rush anyway?
Some of us enjoy Beta testing. :) But, you have to be prepared to run into little snags now and then. That's why it's called Beta.

Errr…
I built my first Firebird (Phoenix really) at 0.6

I posted here due to the fact, at least for me, that only the Avast forum is effected.
Cheers
;D

Just to add a bit
I have checked other SMF forums, vBulletin & phpBB
All OK