We are attemping to transfer a file using Xmodem through Compuserve. We can successfully connect to Compuserve and login in using a UNIX based C program. When we initiate the xmodem transfer, Compuserve only responds back with C's after each time we try to send the first packet of data. We are using the xmodem/CRC-16 protocol and the receiver is using the same. Is there anything obvious that we should be looking at to remedy this problem.