missing symbols in ndisulator (USB related) ?

Hi,
i need a clarification about what i can expect from the ndis emulator.
I have a couple of USB dongles that i tried on FreeBSD using ndisgen,
and both report problems at load time with the following message:

1. a device reported as
	kernel: ugen1: vendor 0x0cde product 0x0017, rev 2.00/1.84, addr 2
	drivers: WlanUTG.INF WLANUTG.SYS Fwusb1b.bin
   and marked as '802.11g Wireless 125Mbps' (sold by Roper)
   the error message when loading WLANUTG_SYS.ko is
	Jun  2 17:23:38 x1 kernel: no match for USBD_CreateConfigurationRequest

2. a no-name 802.11g device based on a ZyDAS chipset:
	kernel: ugen2: ZyDAS USB2.0 WLAN, rev 2.00/43.30, addr 3
    the error message when loading ZD11UXP_sys.ko is
	Jun  2 17:49:05 x1 kernel: no match for KeDelayExecutionThread
	Jun  2 17:49:05 x1 kernel: no match for KeQueryInterruptTime
	Jun  2 17:49:05 x1 kernel: no match for USBD_ParseConfigurationDescriptor
	Jun  2 17:49:05 x1 kernel: no match for USBD_CreateConfigurationRequest

Now, any idea on how to deal with this ? I am not even sure that USB stuff
is supported under the ndis emulation, though there is a commented
out hook for a variant of USBD_CreateConfigurationRequest in
/usr/src/sys/compat/ndis/subr_usbd.c

	thanks
	luigi