Minecraft crashing only on Kiwike.

[MainDigger]

I experienced a similar problem last night.
The first time i got a major lagspike. So i messed around with OptiFine graphics.
Yet another lagspike ocurred shortly after wich turned minecraft into a greyscreen.
I reset the graphics settings again and tried to login. Minecraft froze as soon as i logged in. And then it chrashed.
I tried to login again several times, more lagspikes and more chrashes.

Perhaps it has anything to do with the mods i got installed. I'll try again later today with an empty .jar.