The reason the v0.4.3 images are missing:
Kthulian was experimenting with a version only update; for example, if you were on v0.4.3 and just wanted to grab the new stuff for v0.4.4, he would pack that separately and you could just download 140 or so megabytes and toss it into the v0.4.3 folder instead of downloading the whole 2.5GB again if you would prefer doing that instead. Really helpful for people who have a data cap from their ISP. However, he forgot to revert the changes he made to the script code and to the files before he released v0.4.4. It was caught practically as soon as the game was released and he issued a fix for it very quickly. I was the one who gave him the idea of putting out a version only release alongside the normal release, so you can blame me for that. I'm pretty sure he's not going to do the version only release thing, so things should be back to normal for the next version of the game.