I just recently received the Mindstorm Invention System 1.0 from a buddy who had never actually used it. Everything seems to work fine with the exception that I can't download firmware to the RCX. I've done all the troubleshooting and support advice that I can find and none of it seems to help. When the firmware begins downloading to counts up to 20 then restarts at 0, after doing this 4 or 5 times it fails. The Troubleshooter says that the IR tower is working and that the RCX is working fine but has no firmware. It also tells me that there is a firmware file ready to be downloaded. Any advice?