Just got 10.6 yesterday and updated to 10.6.1. No problems installing Maya 2009, everything seems fine here!

I think the problem is with the installer of Maya 2009. If you use the service pack 1 release from Autodesk it installs without a hitch.

-J

edit: Meh! Seems the OpenGL viewport colours are borked! Scale and move ocon is grey all the time, no RGB for XY & Z.