Comment # 3 on bug 89203 from smoki

 Try mesa git or 10.5.0-rc1 or up, or just patch older mesa... i am mostly
thinking of this patch:

http://cgit.freedesktop.org/mesa/mesa/commit/?id=a338dc01866ce50bf7555ee8dc08491c7f63b585

 Not sure if helps Minecraft exactly, so it is just a guess because i have
another games which stutter similar to what you describe before it.