Wha? They have different compression methods for gamestudio??

The images look exactly the same in the image editor. It's only in gamestudio they look different. In that picture I showed, both are from gamestudio. In fact I made the left image from the right one.

I've never had bitmaps "butcher" any image in any other software, and they always are the same size unless I compress my TGA's, or add the Alpha Channel.

EDIT: I just did a test, and the bitmap output is the same in 16-bit to 32-bit modes. I'll ask around on the bug forum and see what's up.