I've tried all the recommendations and WIKI instructions and I have not been able to attach to my gumstix as a USB gadget. 
My host machine is a Mandrake 10.1 box.  I started out with Mandrake 10.0 and upgraded hoping that might fix the issue.  Didn't.
I have run menuconfig many times toggle between USB Ethernet gadget with and without RNDIS support.  Seems to make no difference.  Except without RNDIS support I cannot see the USB gadget on my host machine.
1.)  Any suggestions?
2.)  Would someone like to make available an image that has been tested.  One that makes the gumstix appear as a USB Ethernet gadget on a Linux box.
I'm desperate.  My one last hope is the USB root hub on my machine has issues/is old and installing MDK on a newer machine may configure MDK with some missing needed support.  And I'd really like a tested gumstix image, :-)