OK, the expert is here. No one hangs themselves in The Wizard of Oz. I don't even know where that came from. That scene has some birds in the background, but none of them remotely look like anyone hanging.
And apparently, I'm one of the few people here who has played Dark Side of the Moon with the movie. Yes, it is definitely synched. I don't see how it could be unintentional. And the song Money (with the cash register sounds) doesn't start when Dorothy has gold or money. It starts when she opens the door to the munchkin land, and the movie goes from black & white to color. Another interesting note, the end of the first song has some strange sounds that seem to go on for an arbitrary length of time. However, after watching with the movie, you can see that the timing was all planned. Song1 ends abruptly and song 2 begins with an alarm clock ringing as soon as they show the witches bicycle (well, she isn't the witch yet). It's definitely worth checking out.
There are web sites that explain the similarities. Some are real, and some are real stretches. I don't think it works to loop the CD after it ends. It ends before the movie ends, and the phenomenon ends there. But one thing I'm intrigued by is when they show the fence on Doronthy's uncle's farm, you can see a triangle hanging. And the way the wooden beams in the fence are angled against the triangle, it looks like the prism on the Floyd album cover.