The "Sticky Keys" bug causes the Minecraft client to act as if a button hasn't been released when it has - which causes your character, Steve, to suffer some awful consequences as a result (depending on what situation you are in when the bug occurs).
Upgrading the LWJGL libraries/drivers that come with Minecraft usually fixes this bug. To upgrade the drivers, do the following:
- Download an updated version of the LWJGL libraries
- LWJGL 2.8.0 - Not the latest release, but worked great for me
- Copy the following files from
lwjgl-2.8.0/jar/in the zip file you downloaded to
/home/[youruser]/.minecraft/bin/, replacing the existing files there:
- Copy all of the files from
lwjgl-2.8.0/natives/in the zip file you downloaded to
/home/[youruser]/.minecraft/bin/natives/, again replacing the existing files there
If you still encounter issues with the new versions of the libraries, try a newer or older version until you find one that works with your system. 2.8.0 happens to work for my setup (Debian Stable w. Sun Java), but YMMV - your Minecraft may vary.