after getting Logic Studio I've found out that GPO doesn't work as a AU plug in there. I can insert if and open the instrument but after pressing "load" I get the yellow box with dry, wet audition and multis but clicking on any of them does nothing...I can't load any samples ?
I've been having the same problem, and I can't get GPO studio to work either since I installed KP2. There's a sticky thread above that covers this topic, and at least one possible solution, try looking there.
I have Logic Studio and no problems with GPO KP2 except that you have to kinda click once and then hold your mouse on the instrument drop-down, keep your mouse next to the arrows, and then you can load your instruments.