Login Trouble

[Paul Trevethan]

I am brand new to Ubuntu. I am really liking it so far (on test machine)
but I have an annoying little problem someone might be able to help me
with,

Not that you have to reboot a Linux machine much, but when rebooting, I
get to the login screen, do the login/password and get an error
saying my session lasted less than 10 seconds and the cause could be
"something about permissions" (don't quite recall exact words) or
insufficient disk space?.

I can fix it EVERY time without fail by simply restarting the login
session as a 'failsafe terminal' session, deleting the .ICEauthority
file in my home directory and exit the terminal. The login comes back
again and works just fine.

I have NO idea what is causing this or how to fix it "properly"?!

I am not familiar with the workings of the .ICEauthority file or in fact
with gdm graphical login. In all other linuxes I have used I boot to
shell prompt and run gui using startx command. That approach uses a
different set of files to gdm I believe. In fact I don't even know how
to do that in Ubuntu, setting '3' in inittab file did not seem to work?

Hope this is easy answer?
Paul.