Whenever I log on to the server, it lets me play for a few minutes, then crashes and gives me this http://pastebin.com/rxsdVndt It looks like nothing's wrong, so I'm not sure what the problem is. Any help? EDIT: I crashed again and got a different error: http://pastebin.com/gHXwXYHq
All I can see are a few errors with the lwjgl sound system, and further up it seems lwjgl is having an issue with vsync, I don't know if those are the source of the crash or not. Maybe try updating lwjgl, here is a guide: http://www.minecraftwiki.net/wiki/Update_lwjgl
On the second crash, it looks like you got an Out of Memory, try searching sk's post about Permgen, he also explains how to "install" it to your game. BTW you can also try updating your video card drivers, and as Nolan said, update LWJGL (wich should be updated with the game, so it's abnormal if the bug comes from here).
You should also update your launcher, just saying. http://skcraft.com/threads/alice-patch-8.1355/#post-13766