Well, for your first issue with the NSAutoreleasePool, I would use instruments so you can trace where the extra drains/releases are coming from.
Your second issue doesNotRecognizeSelector is telling you that the selector that is being called doesn't exist (or lost scope). I would use the debugger so you can, again, trace that code execution.
You get a message "xxxxxx does not recognize selector yyyyyy" usually when an object has been released but you are still trying to use it. At that point because the memory is random, the system thinks it's some other random kind of object (like UIImage). Thus it's a red herring, a sign that something else is wrong and you are over-releasing an object.
There's no way you are getting those weird autorelease messages unless you are doing SOMETHING with a custom autorelease pool. Fess up, what are you doing with an NSAutoreleasePool in your code?
I think they are probably related to the "does not recognize selector" messages since you may be over-releasing things because of this.
Ok, I left if at adding a -(void)scale to a subclass of UIImageView and using this new class. Tested it, works fine on 2.2.1, 3.2 and ios4, both on simulator, iphone touch 3g with ios4 and ipad with ios3.2.
I still need to get ahold of an iphone4 and see if some weird layout problem comes across (I still believe the problems appeared when the Os want to blow things up to the new retina display).
Not being in the US is going to make it a tad hard though