My character refuses to turn. I tried moving using the mouse, WASD, and arrow keys, but my character always faces the same direction.
A workaround I found is pressing the Enter key twice, which allows me to turn for less than a second before locking up again.
If it matters, I'm on Ubuntu 10.10 64-bit, and using sun-java6.
If you read further down the thread list, you would have found this:
http://forums.spiralknights.com/en/node/2193
Please read through that and tell us if any of those things help; your problem sounds a little different from the one in that thread, but please let us know if your situation improves at all.