I'm using Kubuntu, and I switched the default browser to my favourite one. The thing is, when I did this, both my Twitter clients stopped working. Now each and every Twitter client I download and install fails to open any web browser to finish my account authorization. It's impossible they're all broken, so I reset my default browser to rekonq and it works well as a default browser, but still can't login to twitter from any client. In fact, every button in every program that should open a browser window (like Amarok with the "like on last.fm" button) does nothing. So I think there may be a problem with my system but I can't figure out what is it.

My user is not in the admin group (it's a shared user), I have an admin user but I only use it to install programs. Could that be the cause? Also, hitting alt+F2 and writing man:file (enter) opens a rekonq window normally.