[lug] Laptop with external screen?

[Rob Nagler]

I just got a laptop running Centos 5.4.  I want to run it dual-headed
when I'm at my desk, and just with the builtin screen when I'm out and
about.  Xinerama does fine, but it doesn't detect that the external
display isn't there.  This is a known "bug".  While I've seen
solutions where I can reboot to fix this problem, this is annoying.

Anybody know of a solution to this problem?

Thanks,
Rob