Other Help Topics :: Can't enter "@"-sign in Firefox!

Just a small problem, but for some reason I can't enter the commercial at sign in Firefox (e. g. in online forms, URLs, etc.). I have German keyboard layout and this problem doesn't occur e. g. in Beaver or Ted.
Any ideas? Many thanks in advance.

Did you choose your keyboard map? (see DSLPanel)

Bien sur, as the French say. (Hey, the circomflexe isn't working either!!!)
I use de-latin1 (not de or de-latin1-nodeadkeys).

original here.