h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

First off, I am new to the site, so if I'm doing something incorrectly, just call me on it, ok?

Now down to buisness. I have a cat who we rescued when he was 4 weeks old off the city streets. He is now a year old, fat, and insane. He will walk a few steps, bu then collapses and rolls onto his side. If he is chasing something, he can go for an hour without exhibiting this behavior, but I was wondering if this happens in any of your cats. We have had 5 other cats and none of them were ever so strange in this respect (we've had some oddballs, though). I am hoping for some feedback, so help me out!

I have a cat who also does that, but it is only because she wants us to take notice of her, and fuss her, she does it in the most awkward of places. She also likes to sleep either on top of the computer monitor, or the television she likes the warmth, but also the attention when we move her tail out of the way.