I am using Gentoo Linux and I have been trying to figure this out for quite some time. When I run startx gnome starts and loads the splash screen but stops there. the only line in my xinitrc file is exec gnome-session.

I was able to login to gnome sucessfully twice. It seemed to be at two random times and I have tried so many things I'm not sure what i did. But after I logged in I logged out and tried to login again to make sure it was working and of coarse it did not.

I am currently re-emerging xorg-x11 to see if that fixes the problem. I haven't tried kde, but I will to narrow down the problem. Also think it could be related to sound or iptables.

When I kill the bonobo-activation-server process I get some errors about gnome settings not loading (sometimes). Any other ideas? I wish I could get an error message or something.

check your .xsession-errors file

Somehow I resolved this problem. It was possibly a problem with iptables so I turned it off for now. It could have also been a problem with alsa modules which I disabled. Haven't played with either since I got it working because I barely use sound at work and if it aint broke, don't fix it. (I started and stopped X a few times to be sure it works consistenly.......but haven't closed X since that day....fingers crossed.)