I just encountered this problem recently so I thought I would drop a short note about it. Once I was trying to mount ext3 filesystems with read and write support and I, by mistake, did chmod my entire root partition as 775.
In this process, I made a warning message appear everytime I login, saying something like the home directory should be accessible by only its owner and should be set to 644. In addition, it also said that the file “$HOME/.dmrc” should be blah blah blah.
First, I made my home directory into 644. Then it won’t let me login saying it was not able to access my home directory. If I set it to 755 then that damn warning message I mentioned earlier reappears (What do I do?). Then what i doubted was that “.dmrc” file.
WHAT TO DO?
I just set the permission of “$HOME/.dmrc” to 644 , leaving rest to be in775 and it worked like a charm. I now am able to login and no warning message appears.
I hope this will help you too.
[Editors note: Here’s a good example of why you should not mess with user permissions and chmod/chown commands if you have no idea what they do]