Well, the information for SC1425 is incomplete. Keyboard works for _i386_ bsd.mp, and doesn't work for amd64 bsd.mp. In my experience running i386 was more fruitful than amd64, so I think it's important to make a difference.
For me, I get the same result with the MP-generic for both i386 and amd64 with SC1425. Standard works fine, MP doesn't. Anyhoo, most of the times there won't be any keyboard attached to it, so.. I'll just use the amd64 MP and a USB keyboard for now as long as there are no other signs of related/non-related problems.. :) /Anders