Well, like I said, it was a MD, not Hi-MD player. It's the MZ-S1 netmd player. I don't think it works without a battery even when plugged in the USB port. I didn't think the newer himd players could transfer just using usb as a power source.
SS was crashing on me before, and I figured out that I had to put in a brand new battery (e^2) then it worked perfect. Though this was for a MD (not HiMD) player. They seem to be very picky about battery strength for transfers. Just a guess.