Gosh, that had been two unproductive days in the matter of working with my browser. I just updated to firefox 22 and pentadactly was not working anymore. So i had to work two days without a usefull userinterface. I'm happy the current nightly build (Pentadactyl Nightly 2013-06-29) has raised the supported version to 24. So you can update your firefox and just install the newest version of pentadactyl :-).
And please donate to that lovely piece of software, i can tell you the last two days weren't the same.