G1 crashes with:
;; Using jvm: "/export/local/common/jdk/baseline/solaris-i586/jre/lib/i386/server/libjvm.so"
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/tmp/jprt/P1/200135.jcoomes/source/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp:1635), pid=18483, tid=10
# assert(old_end != new_end) failed: don't call this otherwise
#
# JRE version: 7.0-b147
# Java VM: Java HotSpot(TM) Server VM (22.0-b08-internal-201110142001.jcoomes.hs22-b08-snapshot-fastdebug compiled mode solaris-x86 )
# Core dump written. Default location: /export/local/55625.HSX.PIT.VM_solaris-i586_bigapps__server_comp_runThese/results/runThese/core or core.18483
#
# If you would like to submit a bug report, please visit:
# http://bugreport.sun.com/bugreport/crash.jsp
#

--------------- T H R E A D ---------------

Current thread (0x09288400): VMThread [stack: 0x7497f000,0x749ff000] [id=10]

Stack: [0x7497f000,0x749ff000], sp=0x749fd130, free space=504k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x1df6ca8] void VMError::report(outputStream*)+0x904;; void VMError::report(outputStream*)+0x904
V [libjvm.so+0x1df7e59] void VMError::report_and_die()+0x56d;; void VMError::report_and_die()+0x56d
V [libjvm.so+0xb4b5fe] void report_vm_error(const char*,int,const char*,const char*)+0x53a;; void report_vm_error(const char*,int,const char*,const char*)+0x53a
V [libjvm.so+0xcb131e] HeapWord*G1CollectedHeap::expand_and_allocate(unsigned)+0xb1e;; HeapWord*G1CollectedHeap::expand_and_allocate(unsigned)+0xb1e
V [libjvm.so+0xcb00b1] HeapWord*G1CollectedHeap::satisfy_failed_allocation(unsigned,bool*)+0x389;; HeapWord*G1CollectedHeap::satisfy_failed_allocation(unsigned,bool*)+0x389
V [libjvm.so+0x1e2cadd] void VM_G1CollectForAllocation::doit()+0x21;; void VM_G1CollectForAllocation::doit()+0x21
V [libjvm.so+0x1e2a272] void VM_Operation::evaluate()+0xe2;; void VM_Operation::evaluate()+0xe2
V [libjvm.so+0x1e28540] void VMThread::loop()+0x788;; void VMThread::loop()+0x788
V [libjvm.so+0x1e27749] void VMThread::run()+0xc1;; void VMThread::run()+0xc1
V [libjvm.so+0x195ac13] java_start+0x6fb;; java_start+0x6fb
C [libc.so.1+0xa7045] _thr_setup+0x4e;; _thr_setup+0x4e
C [libc.so.1+0xa7330] __moddi3+0x60;; _lwp_start+0x0

VM_Operation (0x74458e30): G1CollectForAllocation, mode: safepoint, requested by thread 0x0b491800