He hee, has he had a growth spurt? Put on a bit of weight? Gotten longer, or chest got deeper? This will throw off a growing cat's balance, aim, etc. They suddenly turn from kitten to CAT and have to push off harder to make the same arc!

I've seen it with a few of mine, and it really is just a day or so thing. They have to adapt fast in the wild, or be caught. So if you are in a busy mode of life, you can miss it completely.

Here's hoping that is all it was!