if reiserfsck does not find any corruption that means that reiserfs on-disk structures are consistent. no rebuild operation is needed.
[....]
so, can you give me advice on this? should i still backup this parition? (it's my root ( / ) partition, so it's not that important)
reiserfsck is considered as stable now, but backups are always useful, thus you would have this dozen of files backuped now.
hm, yes, that makes sense. i am already suspecting some application, but i'll watch out for further corruptions.
Thank you for the quick (!!) response, Christian.