Ever seen anything like this in your logs?

/home/username/.forward.hostname: Group writable directory: 675 Time(s)
/home/username/.forward: Group writable directory: 675 Time(s)

The problem is caused if you have a mailserver setup, it looks in your home directory for a forward file. However, if your home directory permissions has strange privileges (such as being group writable) it complains about it, which gives you these harmless (but annoying) messages.