The API works with Roku 2 XS Model with 6.1 build 5518. But it doesn't work on Roku 3 with build 6.1 build 5517.
Also on Roku XS, the API doesn't work if TV is switched OFF. Only works if Cable is disconnected. This doesn't seem to serve the purpose.
Re 6.1.5518 working and 6.1.5517 not working - that is strange. Even stranger than a fw release from a newer date having a smaller build# than an older beta 8-)