Excuse me if this has been posted here before, I tried searching and found nothing. I'm trying to install a software compatibility upgrade and when I get to the portion where I must put in my Admin password to continue, it "accepts" the password and then just returns to the same screen. No advance in the installation whatsoever. I can go back, but I cannot go forward, no matter how many times I enter my password. Same thing goes for uninstallation of any program, trying to unlock locked portions of the System Preferences, anything in the OS that requires a password unlock is not working. Like I said, I can enter the password but nothing happens after that. I can log into the computer, and that's it as far as using the password. I'm running OS X Lion on the latest generation Macbook Pro. I also have a partition running Snow Leopard. I've tried booting into Recovery HD and repairing the permissions in Disk Utility, which doesn't seem to help. Any help is great, thank you.