I don't have a solution but I can confirm your problem. I just posted almost the exact message. My transfer stops at 44% everytime. When I play it back from the MZ-RH1 it plays without a problem. My guess is some sort of buffer overflow. The transfer seems to bog down. You can see the time remaining begin to que up. I've tried the transfer with my Laptop which has 1 gig of memory and my desktop which has 2 gig. The first couple of times it happened I initialized the disk and rerecorded. The transfer when thru. This time it didn't work. I almost sure it's a bug.