Wow, thanks a lot! I think you nailed it. The underlying filesystem is in fact ext2 (i am not entirely sure why it worked in the beginning but i figure there is a possibility that i had a tmpfs mounted during my experiments and not the real final filesystem).
So the "workaround" is probably to use something that isn't ext2. That should'nt be much of a problem. The only reason i was using ext2 in the first place was that i could automate generating disk images using mke2fs but since i've already setup a vm for automated package building anyways i guess i could also use it to build disk images and completely skip ext2 in favor of a more "native" filesystem.
As far i as i am concerned the thread can be closed as solved or am i supposed to do that? Sorry, i am not entirely familiar with the customs around here yet.