INT0 on D- instead of D+

Hello,

I've got a board already in production that has INT0 connected to D- instead of D+. See: http://www.retronicdesign.com/wp-content/uploads/2012/07/UsbJoyAdapter.jpg
Is it possible to modify the behavior of V-USB to accept this?

I already tried couple of things but it does not work. I doubt there is something to modify in the USBDRVASM.

Anybody experimented that before?

Thanks!

Nitz