I must have been tired the other day - I misread your model number. Sorry about that.
The good news are that my laptop is up and running again, so I have access to the xorg.conf files. If you ever get a "time-of-day clock stopped" message directly after post, I know how to fix it..
With the exception of the twinview config, which I basically copied from the site I referred to in the previous post, the configs are exactly as Ubuntu set them up. Not much magic here, so I guess that they should work directly on your M90. Good luck!