Email me (hugo@empeg.com) with your address; we have some spare IR filter material (looks black, is transparent to IR). If you put a bit of this on the back of your display filter (the blue/green/amber/red stuff) in front of the IR sensor it may help it not get swamped by ambient light.

This used to be fitted to mk1s, but the mk2 sensor has an integrated filter. This might help though.

Hugo