This has been confirmed to work on:

Sandisk cruzer micro  4GB (with U3 removed); older PNY 1GB; if anything else works, or just to contact me, email me at dudeman@dude-man.com 

I installed puppy to USB, right? Well... it didn't work at first with superfloppy mode. Before you begin, burn a puppy linux cd. I used Burning Thunder Pup. Boot it.