XWoM Client doesn't load a main Map with bigger size

[WLanMichi]

Hey !
(Sry, im German, my texts are sometimes senseless or a little bit misspelled.)
Okay, i have a problem.
When i load my Server, with a Map wich is X:256 Y:256 Z:256 it shows the motd in the screen , normally ^^
but after the load screen, it crashed. I know, that comes from the big Main-Map.
But i am not the first one, who have problems with this.
So, is there any way to stop the crashes?

** I started mcdzienny with a .Bat Launcher + more ram, but it crashed against. **
A screenshot is aviable :
http://i.imgur.com/UbBQc8y.png (Thats the error , when i try to connect, after the loading screen.)

[Conor]

I get the same error occasionally, I see it more often when I load big maps.

I remember one day I couldn't physically access a 256 x 256 x 256 map because I always got kicked with this error.

[HelloWorldCool]

well since this is a main map...

how about turn physics off, and possibly turn lowlag on?
Physics off on main map though should help.

[dzienny]

There should be no problem if you use Java6. Make sure you do, as Java7 breaks the minecraft classic.