repeated game crashes after 5-10 minutes whilst on the server

[miner-sd]

I've had repeated crashes on the mianite server and i don't know what is causing it but here's a crash report:
http://pastebin.com/ZyXPmDJe

[miner-sd]

i have many crashes online, but none on singleplayer

[Anima-Sanguis]

same.
here's the pastebin: http://pastebin.com/3radBGuf

[Anima-Sanguis]

ok, i fixed it, i just had to remove optifine from my client

[miner-sd]

i haven't been having any optifine issues, but on my crash reports it always displays this line of text:

[B#347] # The crash happened outside the Java Virtual Machine in native code.