Just some food for thought. I can run this, and extrabiomesXL (which everyone says has issues) and quite literally 160 other mods at once on my home, WIn7 64 system. The linux server can also run it, without crashing, but any client connecting recieves a ticking screen or similar problem in this line:
Which I guess has to do with how the server is sending out new entities spawning into the world. Linux servers botch up the packets and clients get booted since they handle the information a bit differently. (Will happen randomly if the server is running under normal load, but as soon as it gets up to full steam with alot of people/chunks loaded, it sends these derped up packets out constantly and boots the clients.) I confirmed this on 4 different linux based servers, as well as my home linux test server.
I'd be interested to know if other people having the same error messages as I've been getting are trying to run off a linux system.
I've had the same issue on 64 linux on a home server. unfortunately the solution was to remove MoCreatures v4.5.1