I disabled the cropping of images to see my images and thumbs as they are, uncropped.
After ugrading from 1.2.1. to 1.2.2. this feature is still disabled under theme options, but in reality the thumbs of the albums are cropped, but those of the imagethumbs are not.

A little bug I guess. Hope you find a fix soon.
See it here

To see thumbs of uncropped images you need to be using the ...ThumbMaxSpace functions.

Imho I think we have a misunderstanding here, because I'm using my own theme from 1.2.1. and the thumbs are shown uncropped for the imagethumbs but it's just the albumthumbs that are cropped. I didn't change anything about my theme.
Using printCustomAlbumThumbMaxSpace() is in the case I want to control the exaxt dimensions, but I want to use uncropped images with the give 'longest side' as entered in the theme options page. When I use printCustomAlbumThumbMaxSpace() and set the dimension to max 150 with and max 150 height I get square thumbs and I don want that.

I've used this in my theme of 1.2.1 and it always gave me the correct uncropped albumthumbs:
printAlbumThumbImage(getAlbumTitle())

And when I use this:
printCustomAlbumThumbMaxSpace('',150,150,'',NULL,false)
I get cropped images again.

Actually the ...thumbmaxspace functions should work for album thumbs, too. I will try to reproduce that later.

I'm sorry to 'bother' you again, but with this code:
printCustomSizedImageThumbMaxSpace(getAnnotatedImageTitle(),150,150,'','')
in my search.php I also get square cropped images, so it seems this is even working for the imagethumbs... and in my admin I really have 'cropped' unchecked.

I used this code before and that went ok:
if (getFullWidth() === getFullHeight() OR getFullWidth() > getFullHeight()) { printCustomSizedImage(getImageTitle(), null, 150, null); } else { printCustomSizedImage(getImageTitle(), null, null , 150); }

Really, do this function still not work correctly....Unbelievable how these quite small functions bug us... We will check that.

Unfortunatly I am able to reproduce that something is not correct here. So far printCustomAlbumThumbMaxSpace() seems only to work uncropped if the width and height are not set to the same value. 151x150 gives me uncropped album thumbs but somehow they are stretched in widht or height then.
printCustomSizedImageThumbMaxSpace shows the same behaviour but does not stretch the thumbs.

I am really confused because the last time sbillard and I worked on that maxspace functions and checked that did work... I swear...

I believe you when you say it worked , but ZenPhoto gets more and more code and I guess it gets harder to predict the outcome of one change to everything else?
But I'm sure this will be solved. Hopefully it will take not too long though, I was so happy I finally got my not squared or cropped thumbs to nicely center inside a box :=).