Can't update or uninstall Air 3.0 on Mac OS 10.7.2

Whenever I try to update Air, or uninstall with the Adobe Uninstaller I always get the same error message.

An error occurred while installing Adobe AIR. Installation may not be allowed by your administrator. Please contact your administrator.

Of course I'm the administrator...

I've tried all the tricks in this forum:

• disabling graphics card switching
• opening google chrome
• opening firefox

Nothing works.

This is very frustrating, I can't even roll back to 2.7.