You bet, it's LRPD-Tastic.
I believe it's only supported since Moz 0.9.6. IE must use some different format for doing their 'favicon' thing.
A quick check of The Reg reveals...
<link REL="SHORTCUT ICON" HREF="/favicon.ico">
I'm guessing that's the one that make IE do it's thing. But, umm, who cares? :)
Anyway, yes, looking lovely in Moz, thank you kindly. Makes tabbed-browsing far too easy, with a nice big LRPD staring at me...