Rated 5 out of 5 stars

yazan: broni tarih: Mart 23, 2011 ·

Got it.
Tracked it down to FastestFox add-on.
Uninstalled it and FireFTP works just fine.

This review is for a previous version of the add-on (1.99.2.1-signed).  This user has 2 previous reviews of this add-on.

yazan: Mime Čuvalo (Geliştirici) tarih: Mart 24, 2011 ·

I'm currently talking with the author of FasterFox to find a solution - seems to be a problem on their end...