urtw0: could not allocate USB transfers

[joseph]

Hello,

i decided to get my laptop wlan via usb because my internal device isn't 
supported yet.
The usb device is a logilink WL0006 unit its vendorid is 0x0bda and the 
productid says 0x8187.
My search results say that this device depends on a RTL8187 chipset.
I tried both, load the kernel module at boot time and compile kernel 
withe urtw, but i get the same output at dmesg

device_attach: urtw0 attach returned 6
urtw0: <vendor 0x0bda product 0x8187, class 0/0, rev 2.00/2.00, addr 2> 
on usbus3
urtw0: could not allocate USB transfers, err=USB_ERR_NO_PIPE
device_attach: urtw0 attach returned 6

im running FreeBSD 8.1-RELEASE-p2 amd64.

What might be the reason for this error?
Thanks for all hints.

regards

joseph