Preventing glx from auto-loading?

[Bryce Harrington]

In Ubuntu we're turning Compiz on by default, however we've run into a
problem glx is getting automatically loaded for drivers like
vga/vesa/vmware that don't support it, which we believe causes some
crashes we've run into.

We've tried both with xorg.conf's that omit a Modules section, and
xorg.conf's containing a Modules section that omits glx, yet from
Xorg.0.log it appears glx gets loaded in all cases.

What is the proper way to force a module (i.e. glx) to NOT load?

Thanks,
Bryce