I have the power measurement part of my overall domotica setup working.
It was a bit of a pain because I had an IR Led on my (Eneco) power meter.
But I have it working eventually ... the trick with the Reflective-Optical sensor is that I had to cut the white wire in the 3,5 jack. (Not blue or the copper ... but the white wire)
More on this project can be found on my personal blog --> http://blog.i-1.nl/?page_id=340
