uhmodem crashes netbsd-5/i386 on attach

[Dennis den Brok <d.den.brok%uni-bonn.de@localhost>]

Hello,

I'm having trouble with a Huawei USB modem on NetBSD/i386 5.0_STABLE.
When plugging it in, I get the following crash (everything transscribed
manually...):

uhmodem0: HUWAEI Technology HUAWEI Mobile, rev 2.00/0.00, addr 2
ucom0 at uhmodem0 portno 0: modem
ucom1 at uhmodem0 portno 1: alt#1
uvm_fault(0xc05fca0, 0, 1) -> 0xe
fatal page fault in supervisor mode
trap type 6 code 0 eip c0473641 cs 8 eflags 10282 cr2 5 ilevel 0
kernel: supervisor trap page fault, code=0
Stopped in pid 0.36 (system) at netbsd:usbd_attachinterfaces+0x131:     movzbl 0
x5(%eax),%eax

bt yields:
usbd_attachinterfaces
usbd_probe_and_attach
usb_new_device
uhub_explore
usb_discover
usb_event_thread

I hope I don't need an exact transcription of this for this report
to be useful...

The device normally also exposes two umass devices, so the crash
might happen when attaching them. On a different machine, the
crash does not occur; instead, only the two umass devices are
detected, but no uhmodem. Also, one of the umass devices is recognized
as a CD drive, which is most likely nonsense. A kernel with
options USB_DEBUG
does not print anything related.

Can anyone help?

TIA,

Dennis den Brok