If you're using the Sharp IR sensor as an obstacle detector on your ArduRover, you should know that it doesn't see left and right equally. Here's some good analysis on its real detection pattern. So you might want to tilt the sensor a bit to the right.
Comments
That's great analysis, and good info.
On the Solarbotics.com site they describe the issue of having the IR emitter next to the PSD for the sharp sensor, in that it always detects the reflection at an angle. The emitter for IR light (or any diode type source) is much more directional, than say ultrasonic sound, where equal spacing between the emitter and sensor is less of a problem, and behaves as expected.
But as you say, just offsetting the sensor by a degree or too can eliminate the main problem, it's just make my BrutusBot look boss eyed ;-)