Hmm, i see what your saying, but i think i know of a way you could do this, and keeping your Images Hight/Width ratio.

So, let me give you an example of what i think your trying to do:

Lets say you modeled a Bar of Soap (or something else that was oblong in shape) and you are trying to project text onto the side of it, but don't want it's funny shape to ruin or warp the text.

Does the above sound like what you are trying to do?

If so i might have a cure, but it's hard to discribe. I would have to post a couple of images for you to follow. (which i wouldn't mind doing) but i don't want to do it if i'm not talking about the right thing..... you know what i mean?

Anyhow, post back if you now what i'm talking about and also correct me where i'm wrong.

Have fun!