How to elminate "unsigned driver" install error for RNDIS driver on WInXP?

We have an application which uses the RNDIS USB driver, aka "Linux USB Ethernet/RNDIS Gadget" to talk to a linux based embedded device.

We have digitally signed (with a Verisign certificate) this driver for use with Windows 7. This eliminates an "unsigned driver" error message on install.

On XP, however, even a signed driver displays a "Linux USB Ethernet/RNDIS has not passed Windows Logo testing..."

This is, evidently, a driver developed by Microsoft. I saw reports that this and other drivers were signed in SP2 and this broke in SP3.

The goal is to do an开发者_StackOverflow install of the driver without a warning or error. Is this driver, or a compatible driver, available anywhere else? Is there a way to get it signed through WHQL?

According to http://en.wikipedia.org/wiki/WHQL_Testing:

A company can choose to sign their own drivers rather than go through the WHQL testing process. These drivers would not qualify for the "Certified for Windows" logos, but they would install on 64 bit versions of Windows and install without a warning message on 32 bit versions of Windows Vista or Windows 7.[2] However, it will not install without a warning message on Windows XP.[3]

I read something somewhere about how to get around this but can't find it right now. Can you not get it (or a renamed copy of it) signed through WHQL?