IR Sensor Problems — fried?

[PuiChi]

[font=Verdana]For testing purposes, we hooked up 1 servo with 2 unshielded sensors, and they worked fine. When the beacon was on, the servo would stop, recieving IR; when the beacon was off, the servos would move in attempt to locate the beacon. [used tracker.zip]

However, after we shielded 4 sensors with shrink-wrap tubing, mounted them on 2 servos, and tried the sensors using the same code, the servos kept moving and sensors didn't see any IR, even when we stuck the sensor right infront of the sensor. We attempted using both PWM1 & PWM2 on the beacon, also all PWM-DIGI combinations on the servo and sensors.

Did we fry the sensors when we shrink-wrapped the tubing over the sensors, or is it something else? o____O;;

Please Help--!