After playing for a while, with good performance, a few levels in, the screen will often be unresponsive, and then teleport me to whichever direction I was headed. This never happens When I've just started up the game, but will progressively get worse until the game is unplayable. Since this apparently affects multiple people (http://forums.spiralknights.com/en/node/2365), I figured a bug report is in order.
Happens for a lot of people on windows, but also for me, on linux. Using the downloaded client, on ubuntu 10.10, x64. Java is updated to latest version in repo's, using catalyst driver version 11.3.
Please take a look at this, as it makes the game unplayable (can't finish a full tier anymore)