Style-Select in Firefox isn't working

Hallo,

i've defined in fckstyles.xml these styles:

<Style name="h2" element="h2" />
<Style name="h3" element="h3" />
<Style name="Standard" element="p" />

but i can't access the style-select in Firefox - in IE it's working fine & i can apply the styles on the selected text. Back in FF the style-select shows the right style when placing the cursor in a "styled" area but even can't access the style-select.
i've also tried (in fckstyles.xml):

<Style name="h2" element="h2">
</Style>

and i've defined in fck_editorarea.css:

h2,h3,p {
font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
line-height: normal;
}

but it takes no effect?!

Any ideas how to get this working?

Thanks!