Gtk: Ensemble application crashes when selecting anything from ChoiceBox

When trying to select any option from the Choice Box in Ensemble example application (Samples > Controls > Choice Box), the java process crashes with the following message:

#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0xf6da8d31, pid=15658, tid=2914384752
#
# JRE version: 7.0_02-b13
# Java VM: Java HotSpot(TM) Server VM (22.0-b10 mixed mode linux-x86 )
# Problematic frame:
# V [libjvm.so+0x3f4d31] jni_invoke_nonstatic(JNIEnv_*, JavaValue*, _jobject*, JNICallType, _jmethodID*, JNI_ArgumentPusher*, Thread*)+0x161
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /home/platon/Downloads/javafx-samples-2.1.0-beta/src/Ensemble/hs_err_pid15658.log
#
# If you would like to submit a bug report, please visit:
# http://bugreport.sun.com/bugreport/crash.jsp
#
Java Result: 134

I have attached the corresponding error report file to this bug.