Man this is a great post! I was at my wits end trying to figure out why my express card and cable wasn't working (some odd ball null cable apparently). Your diagram is perfect and I can't thank you enough! If anyone is looking for a longer serial cable, just follow double_down's instructions and you can make it as long as you want, just buy the length of cat5 cable you need and the two parts he listed.
**sends double_down a digital chocolate chip cookie**