We went twice in 2005 and didn't see him either time...and we were looking! LOL
We just got back last week and he seemed to be everywhere! Saw him 4 times at 4 different places:
MK in ToonTown Hall of Fame
AK at his breakfast...well, duh...it is Donald's Breakfastasaurus
AK at the exit
Epcot at the Character Connection
And at each location, he was the most animated character...really acting it up and playing with everyone...so silly and fun!
Good luck in you quest. BTW, you can alsways ask a CM when/where to find a specific character and they should be able to help you. Our 2 challenges for our next trip are Jiminy and Capt. Hook.