Steps to reproduce:
1. Open a gnome-terminal window
2. Enable compiz/beryl
3. Open another gnome-terminal window: both will disappear


Stack trace:
I don't have a stack trace. The most useful output I have is this:

jack@nostromo:~$ gnome-terminal       
The program 'gnome-terminal' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadMatch (invalid parameter attributes)'.
  (Details: serial 1449 error_code 8 request_code 72 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)

Other information:
I am running Debian experimental. I have installed gnome-terminal 2.18 and if I disable compiz/beryl, it works perfectly. As soon as I enable it, it crashes.
The Fedora Rawhide ML blames an xorg update for this:

http://www.redhat.com/archives/fedora-devel-list/2007-March/msg00259.html

but changing the xserver-xorg-core package version between 2:1.1.1-20 (unstable) and 2:1.2.99.901-1 (experimental) does not seem to change gnome-terminal's behaviour.

Please let me know if I can help any further!