Weird iTunes/QuickTime Pro problem

I've been working on getting the album art for my albums that iTunes can't get for me and I've noticed something kinda odd.

First, this is what i'm doing......I have album art for every album in my collection but some are smaller than the 320x320 the iPod Touch wants so on those I'll open the picture up in QuickTime picture viewer, enlarge the picture a little bit and see if it still looks decent and if so I'll extract it to that album folder and apply it as my artwork in iTunes. But when I export it, all of the text in iTunes gets noticeably larger. See pics below.

So my question is, anybody know why that's happening and what I can do, aside from closing iTunes down everytime, to prevent this going forward?

The first pic is how it looks normally, the second is the enlarged text after exporting the picture.