OS 10.8.2, LS 3.0.2 "Your installation is broken"

I set up a new Macbook Pro from scratch, on OS 10.8.2, with LS 3.0.2, upgrading from LS 2.5.4. I get the unspecific error "Your Little Snitch installation is broken, reinstall" every time I start Little Snitch Configuration. I reinstalled it several times, and even completely removed it before (including configuration files copied from a previous install of 2.5).
How to proceed?

Jonas