while trying to solve one problem on my system I created another. I followed instructions here:http://linuxmint.com/forum/viewtopic.php?f=18&t=9156
and now I get an error message every time I start Linux Mint, concerning that the file '.dmrc' has incorrect privileges (while it should have 644). Now I tried to solve it by changing the rights for that file. I also tried to solve it by renaming or deleting it, because somewhere else in the net I found this advice which should force the system to create that file new - and of course with the correct user privileges. But in all ways it didn't do anything to that error message.
That error seemed to follow that instructions in that mentioned thread, although I cannot guarantee that there was something else involved. But since I don't have any experiences with Linux user privileges until now I never touched without concrete order from an expert.
What might be important is, that that error message also concerns about the rights of the $home directory itself. I was wondering, whether that could be the key to the understanding of the problem, since I haven't touched it by purpose. But obviously the $home must have specific rights, but I don't know which ones and how to set them.