Panic Attaching USB Devices

I get consistent crashes on -CURRENT when attaching USB devices. This
started a couple of weeks ago, unfortunately I've lost track as to
exactly when. So far only affects one particular system the motherboard
is an Intel 865GSA with ICH5 and a Pentium D 915. My Dell Latitude C400
attaches and detaches USB devices without problem and runs -CURRENT as
well. Both are compiled as of a few days ago. Here's the panic and
trace:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x4
fault code              = supervisor read, page not present
instruction pointer     = 0x20:0xc04c0a86
stack pointer           = 0x28:0xe43ff3b8
frame pointer           = 0x28:0xe43ff3b8
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 32 (usb4)
[thread pid 32 tid 100033 ]
Stopped at      usbd_get_interface_descriptor+0x6:      movl
0x4(%eax),%eax
db> bt
Tracing pid 32 tid 100033 td 0xc402bae0
usbd_get_interface_descriptor(0,0,c06c5000,c40d59e0,80000000,...) at
usbd_get_interface_descriptor+0x6 ukbd_attach(c4614b00) at
ukbd_attach+0x58
device_attach(c4614b00,e43ffc7c,0,e43ffc70,c427beb0,...) at
device_attach+0x58 device_probe_and_attach(c4614b00) at
device_probe_and_attach+0xc4
usbd_probe_and_attach(c3fd3a00,c4203300,2,2) at
usbd_probe_and_attach+0x1e4
usbd_new_device(c3fd3a00,c3f90000,1,3,2,c4040644) at
usbd_new_device+0x2e3 uhub_explore(c3fd3c00) at uhub_explore+0x223
usb_discover(c4043340,c4043340,e43ffd24,c05022d7,c4043340,...) at
usb_discover+0x2f usb_event_thread(c4043340,e43ffd38) at
usb_event_thread+0x8a fork_exit(c04bd304,c4043340,e43ffd38) at
fork_exit+0x7b fork_trampoline() at fork_trampoline+0x8 --- trap 0, eip
= 0, esp = 0xe43ffd70, ebp = 0 ---


This is a reproducible problem so I can try other debugging/test as
directed.

Thanks,
Nick