Hotspot VM seems to crash unconditionally whenever the JVMDI function GetThreadGroupInfo is called. When running java_g the following assertion fails:

#
# HotSpot Virtual Machine Error, assertion failure
#
# assert(is_instance(java_string), "must be java_string")
#
# Error ID: q:\hs1.3\src\share\vm\memory\javaClasses.cpp, 206
#

The non-debug version also crashes, eventually.