Try to put the sensor bar more in front of the TV. Remote wont work proper if too close or too far. About 2 metres is best. Anyway I had somewhat the same problem and puttin the bar slightly more in front of the TV seemed to work fine.
I heard another rumour that putting two candles on either side of the TV at the same height seems to work even better then the standard Sensor Bar. I guess that could work since candles radiate infrared I think.