I notice that in some matches, after I hit space and the move is performed, my joints will not be set to what I had them before.

It always seems to be set in ways that would be advantageous to my opponent, and not just random settings, so I am not sure if this is just some odd bug, or a cheat being used by the other guy.

Sometimes this just happens when you lag, or you have a bad connection.

Or, that's what usually happens to me.

^ this, I see that this happens commonly after the match is reset without the game finishing. It is quiet the annoying bug.

As an experiment try this, when you start a match after something odd has preceded your match, click C a few times. I think this helps clear any odd bits of data stuck. I may have the reason wrong, but the solution seems to work. My clan mate, Tysk1e, recently pointed this out to me.

Answering your Q: It's a bug
When that happens I exit and go back in