I'm running Kubuntu 9.10 and I get the "log in" chimes and cursor when loading into my KDE session, but nothing else. Everything else works, for example I can drop into tty1 and fiddle around, and I can load Gnome. I didn't see anything strange in my /tmp folder such as a X0-lock. so I'm going to look into my /home/.
files to see if I can clear the previous session. I will let you know if I resolve the issue, and please let me know if you have found a resolution as well