Yeah I had Pro Tools 9.0.6 installed on a 2011 Macbook Pro with Mavericks, updated to Yosemite and things seemed to be running smoothly, but the graphics blacking out over drop-down menus issue was driving me insane.
I've been having some major graphics issues anyway (the graphics hardware issues common to 2011 Macbook Pros) so thought it might be that at first, but it seemed too specific. So I thought I would just try uninstalling and reinstalling Pro Tools. Except, having uninstalled it, I can not reinstall it as it says it's not compatible
So will now probably try to revert back to Mavericks or Lion and reinstall from there. Is very annoying.
Also, do you happen to know if the graphics bug is due to Yosemite? I don't remember it being an issue initially when I updated but now I'm not so sure when exactly it started happening.