Just for info here..
I have a transmitter near my cordless phone.
The phone has a plug in headset plugged into the jack on the side of the handset.
When the cable from the phone to the headset is near the IR transmitter, the light glows continuously (depending on position of the cable).
this is due to the noise generated by the phone (it is on hook and in the charging cradle), walking down the cable and the transmitter picking up the noise.
I also have a receiver near my Home theater projector (an Infocus SP-4805), and when the projector is on, I have to position the receiver very carefully (and dress the power lead to the receiver), or it picks up the switching supply for the HPD lamp and swamps out any signal from the transmitters, making it blind to commands to the projector.
So these receivers/transmitters are VERY sensitive to electrical noise and will be blinded if they pickup the noise, so try repositioning the transmitter/receiver/anything that is close to either or both.