Lights, Camera, Actuate?

This is the first time I really ran into trouble - the "Direct Actuation Example" (chapter 6, page 172) doesn't work.

I configured everything as described in the book (Coordinator API (ATAP=2) via USB connected to PC, Router AT on breadboard with voltage regulator, transistor and power switch) but unfortunately the processing code gives me an "XBee request timed out" error.
I can click on the red rocker switch but nothing happens - I just get further timeout errors.
I reconfigured everything many times, re-wrote the firmware and AT commands on the XBees, replaced the XBees with others (I have four at the moment) but I keep getting the timeout error.
I'm quite new to Processing and don't know much about the xbee api - I'm not even sure that this is a software error.

So I'm stuck at the moment. 

As I can see there are some people out there following the blog, maybe one of them might have a solution to my problem.

While I was preparing the direct actuation example I had some issues with the wiring depicted in figures 6-4 and 6-5 on pages 178/ 179 and the text on page 176 describing the PowerSwitch Tail in the book. See the Errata for further information.

There is a new PowerSwitch Tail available at powerswitchtail.com and now they also have a 240 volts version! This might be even better than the one I purchased at ELV (s. blog posting), because you might switch it directly with your XBee (3.3 volts with 3mA!) with no need for the extra resistor and transistor.

And guess what's driving the relay this time? An optocoupler! What a coincidence!