FreeBSD and Xorg: session ending ends up in locked up Xorg server

[dfeustel at mindspring.com]

On Sun, Jun 15, 2008 at 03:46:17PM +0000, O. Hartmann wrote:
> Hello,
>
> I have a strange problem on one of my FreeBSD 7.0-STABLE boxes.
>
> The machine is a FreeBSD 7.0-STABLE/AMD64 box, most recently built-world.
> Whenever I logout from a local X11 session (using Xorg, most recent, and 
> Windowmaker, also most recent, all X stuff recently rebuilt), Xorg eats up 
> 100% CPU time and I never get back to the login box offered by xdm (xdm is 
> driven by /etc/ttys as recommended). Instead I see a weird unresponsive 
> screen with blinking, weird coloured block-graphics and letters, in most 
> cases the same pattern, but this changes. Logging in from another box and 
> killing Xorg gives back the expected login box from xdm.
>
> I have no glue what's going on here. My graphics board is a nVidia driven 
> GF8600GTS and it worked well a couple of weeks ago. I rebuild the whole X 
> stuff incl. all the dependencies because I thought it could have something 
> to do with miscompiled or outdated ports - but thta isn't obviously the 
> fact.
>
> Does anyone see this on his box also?
>
> Regards,
> Oliver

What happens if you login via console and use startx to run X?