and one thing more

when i try to start firefox:

dep@dep-desktop:~$ firefox

(firefox:2619): Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported ExceptionHandler::GenerateDump cloned child 2627 ExceptionHandler::SendContinueSignalToChild sent continue signal to child ExceptionHandler::WaitForContinueSignal waiting for continue signal...

(crashreporter:2632): Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported

again, nothing changed in either software or configuration.

this is very, very weird.