Should be somewhere in this thread: http://forums.taleworlds.com/index.php/topic,113493.0.html
The bits I remember are: Swadia thinks Knudarr Castle (Nords) should be theirs; Sarranids think Almerra Castle (Rhodoks) should be theirs; Khergits think that Nelag Castle (Vaegirs) should be theirs, etc. Basically, most of the border castles. Also, the reason Swadia is usually so screwed is that, AFAIK, it is involved in 3 territorial claims in the beginning of the game.