Loaded jpg's won't fit the mc despite size. Help?

So. I did the xml/flash/thumbnails gallery tutorial with some modifications.
I finally got the whole thing to work and I actually think I understood most of it. But… For some strange reason the jpg’s I load into the main mc just won’t fit into the frame. The upper left is where it’s supposed to be but the picture is enlarged for some reason to the point where it won’t fit the designated area. Which is very odd. Why? Because both the jpg’s and the mc etc are 512 x 384 px in size. Why isn’t this working then? What did I do or not do?
Can anybody help me?
The xml file is exactly like in the tutorial except that my pics are from a local source (which shouldn’t matter since they seem to load just fine, if the wrong size).
I’m attaching the fla file if someone wants to have a look (though the pictures of course won’t be seen, but the programming and stuff is still there).
Any help would be much appreciated. Thank you…
/Riv