Thanks for all the support :/
Luckely I quite like K-Meleon as a backup browser and I almost gave up but I saw there was a new version out today so I coudln't resist trying again
After fiddeling around and merging the profile from Mozilla Firebird 0.7 a few times I finally managed to start K-Meleon 0.8.1.
My merging of the profiles altered the prefs.js so that certain settings specific to K-Meleon where gone after overwriting it.
So K-Meleon asked wich plugins it should load. I said yes to all except for the "IE Favorites Plugin" wich I suspected for a long time beeing the whole starting point for all the problems.
Mozilla had a similar problem a while ago (I don't know wether if it's fixed or not) but if you had a link to a folder in your favorites then during the first startup in wich the favorites get imported Mozilla wouldn't work either (Wich isn't the case here).
Anyway the end result is if I don't load the "IE favorites plugin" K-meleon works fine.
So I added this to my user.js after looking at the prefs.js file:
user_pref("kmeleon.plugins.favorites.load", false);
Is there a limit on the amount of favorites one can have or on the amount of folders there can be?
Favorites dir specs:
Size.......................: 5,69 MB (5.969.041 bytes)
Size On Disk..........: 338 MB (355.368.960 bytes)
Contains.................: 10.711 Files, 1863 Folders
Also renaming the favorites dir to something else didn't help here since windows keeps referring to it and I don't want to mess with it too much.