Installing mods on Minecraft 1.0 does not work for Mo' Creatures

In attempting to get the Mo' Creatures mod working on Kubuntu 11.10 with OpenJRE-6 I get the following error:

#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007ff855ec9c08, pid=4745, tid=140704592516864
#
# JRE version: 6.0_23-b23
# Java VM: OpenJDK 64-Bit Server VM (20.0-b11 mixed mode linux-amd64 compressed oops)
# Derivative: IcedTea6 1.11pre
# Distribution: Ubuntu 11.10, package 6b23~pre11-0ubuntu1.11.10
# Problematic frame:
# C [libX11.so.6+0x35c08] XQueryExtension+0x28
#
# If you would like to submit a bug report, please include
# instructions how to reproduce the bug and visit:
#
#

As per the report's suggestion, I was going to report the bug on launchpad, but figured I'd ask here first. There are others experiencing this as well: Mo' Creatures for Minecraft refusing to work

Any ideas? Mojang recommends 64 bit Java, which is what I'm using. Thanks in advance.

2 Answers

I am a minecraft player and have used many mods, but not Mo Creatures. Do you have any other mods set up that may be causing a conflict?

Submit bug report on launchpad alternatively you can use sun/oracle java see this questions

1. How can I install Sun/Oracle's proprietary Java JDK 6/7/8 or JRE?
2. How do I install Java?