We just upgraded to the long-awaited SMF version 2.0. Unfortunately, this broke the old FF theme. If you switch to the old theme you won't be able to switch back, so please be patient while we fix stuff.
Edit: The old FF theme has been disabled because in its current state it will log several errors for each pageview.
Edit2: I've cleaned up the default theme a bit. Avatars and smileys are available in the SMF Curve and Core themes.