I have been having a problem upgrading some of my 1924's. They are either WS-C1924C-EN, or WS-C1924C-A, when trying to use tftp to upgrade the switch it fails half way through. I have also tried to use xmodem to upgrade it but, it fails right away saying errors during trasfer. I am using 9600, 8, 1, no parity, no flow. I have tried different baud rates and flow controls but to no avail. I wouldn't be worried about this but I can't telnet to the failed switches and users are complaining about no connectivity. If I reset the switch it acts ok for 5-10 minutes, but that is about it. Thanks for your help.