Kernel panic when starting 2nd VM in VBox with VT-X enabled

[lid]

A kernel panic reproducibly occurs on a Mac OS X 10.5.5 host under the following conditions:

1. A VM is already running in VMware Fusion 2.0.1.
2. A VM is VT-X enabled is started in VBox 2.1.0.

The panic occurs before the VirtualBox splash screen shows in the VM window, I think. The panic does not occur when VT-X is disabled in VBox.

Thu Dec 18 16:01:25 2008
panic(cpu 0 caller 0x001A876F): "kernel_trap(0x47337b44) with 64-bit state"@/SourceCache/xnu/xnu-1228.7.58/osfmk/i386/trap.c:338
Backtrace (CPU 0), Frame : Return Address (4 potential args on stack)
0x473379f8 : 0x12b0fa (0x459234 0x47337a2c 0x133243 0x0) 
0x47337a48 : 0x1a876f (0x462680 0x47337b44 0x0 0x10000) 
0x47337b28 : 0x19eed5 (0x47337b44 0x0 0x0 0x47337c48) 
0x47337b3c : 0x58e0f20 (0xf 0x47839000 0x0 0x4785d540) 
0x47337c48 : 0x487e98f8 (0x47839000 0x4785d540 0x4885a420 0x13685f) 
0x47337c98 : 0x487f3db1 (0x47839000 0x4785d540 0x47337d88 0x196963) 
0x47337cd8 : 0x57769284 (0x47839000 0x0 0x1 0x0) 
0x47337cf8 : 0x5776ee25 (0x20005641 0x0 0x57782480 0x106c6c10) 
0x47337d78 : 0x202e0c (0x15000000 0x20005641 0x47337ed0 0x3) 
0x47337db8 : 0x1f619c (0x47337de8 0x246 0x47337e18 0x1da35d) 
0x47337e18 : 0x1ec476 (0x87c9490 0x20005641 0x47337ed0 0x3) 
0x47337e78 : 0x3661c2 (0x58e6ab0 0x20005641 0x47337ed0 0x47337f50) 
0x47337e98 : 0x38cb52 (0x58e6ab0 0x20005641 0x47337ed0 0x47337f50) 
0x47337f78 : 0x3ddd6e (0x7114310 0x1068c1e0 0x1068c224 0x0) 
0x47337fc8 : 0x19f3b3 (0x10696520 0x0 0x1a20b5 0x900ba60) 
No mapping exists for frame pointer
Backtrace terminated-invalid frame pointer 0xb0251e48
      Kernel loadable modules in backtrace (with dependencies):
         org.virtualbox.kext.VBoxDrv(2.1.0)@0x57768000->0x57784fff

BSD process name corresponding to current thread: VirtualBoxVM

Mac OS version:
9F33

Kernel version:
Darwin Kernel Version 9.5.0: Wed Sep  3 11:29:43 PDT 2008; root:xnu-1228.7.58~1/RELEASE_I386
System model name: MacBookPro2,2 (Mac-F42187C8)