Do the channels come in OK after you move the dish, or do you have troubles even when changing channels on the same satellite?
I would be more tempted to say that the polorotor motor (the one that controls the polarity) might be malfunctioning.
If you tune your dish on to an analog channel, and then go into the option to program satellites. Pick the option to auto-peak the skew. Does the picture go fuzzy and then come back in clear, or does the picture stay the same the whole time? If the motor is working good, then the picture should go fuzzy and the receiver should be able to automatically adjust the polarity (skew) for the clearest picture. If the picture doesn't go fuzzy, then the motor could be shot or at least malfunctioning.
The reed sensor is the sensor inside the arm that detects how many 'ticks' go by as the motor is turning so that the receiver can count it's way to the next satellite.
So.. Are you having troubles after moving the dish, or are you even having troubles when changing channels on the same satellite?