Since the distributed version of LWJGL in Minecraft doesn't work with OpenJDK 7 on 64 Bit (Ubuntu 12.04 dev) I tried LWJGL 2.8.2. The problem is after I'm joining a game I'm stuck at the main menu. Clicking on the button "Back to game" will close the main menu and immediately call it again. Only navigating in the main menu is working fine.
I tried build #1459 and the bug still exists but LWJGL 2.8.1 is working fine. But I don't know if this is a bug in Minecraft or LWJGL.
This bug is the same as this bug report (http://lwjgl.org/forum/index.php/topic,4301.0.html). Its because Display.isActive() always returns false, should be fixed soon.
This should be fixed now and part of the next nightly build (after build #1522).
I have tested this with build #1523 and can confirm that the bug is fixed.