I do not know if there's any post about the official aim program for windows mobile. Once I Downloaded Aim Into My HTC Touch Pro, Launched It It Was Incredibly Slow Response Anyone Else Has Problems To This? Or Is There A Tweak To It?
The AIM client has been known to be horrible my friend, It use to be worse, I would say try out IM+ or Palringo.. even beejive found here http://www.beejive.com/winmo/.