I bought the same adapter and have the same problem, I had to shim it. Luckily my after market kickstand seems to clamp the adapter nicely. Other then that it works great.I bought one of those adaptors. Unfortunately, the smallest size (16mm) was still too big for my 12mm dropout. I guess I'll have to shim it a bunch.
Other than that, it fit well enough, and a 203mm disc will fit my 130mm wide frame.