It seems Nokia’s OVI Suite, the revamped version of Nokia PC Suite for next-gen handsets, is keeping its precedessor’s bad habits: basically, it installs an unwanted firefox sync extension (I guess for bookmark sync or something, still Nokia could at least ask, before installing it!).
Since you can’t actually remove said extension from within firefox, you have to act on both your registry and HD directly. Here’s how to remove the blasted thing: