I am running 2 G5's, one a single and one a dual core. I bought and am using 2 wireless adapters from afterthemac and they work great. But after upgrading the OS, I get the same problem on both machines. If you open system preferences, then select network, you are stuck in a loop which says "Your network application was changed by another program". If you click on OK, the same message comes up over and over again. You can force quit system preferences, but when you select network again, same problem. Does anyone have an idea where this would be coming from? Support at afterthemac mentioned it could be from a security patch as part of an OS upgrade....any help would be appreciated.