also, if you look at the diagram in the manual for the computer interface cable, they have pins 2 and 3 wired wrong on the PC side D9 connector. You need to swap pins 2 and 3 on the PC side D9 connector. TX and RX.
Just thought this might be causing some problems for people doing PC control that tried to make their own cable. This caused me some grief for about a day until I looked closer at the diagram.