As of last night, I have been unable to play the game. It will launch properly and everything, but after about a second, it blackscreens. The cursor still appears, but nothing else. If I minimize and reopen the game, the video works, but only for about a second. I can click buttons while the video isn't working. Everything except the video works as expected. I did download the newest update last night, but I can't say for certain if that is the cause. I recently updated Java, but I think I played Spiral Knights since then.
Oh, and Windows 7 Ultimate, NVIDIA GeForce 555M, i7-2860QM. Not sure how much that helps, but it can't hurt.
EDIT: The problem is now fixed. You may delete this thread.