"Cherry switch" - a stupid question?

Yes, move it to the same spot, faced the same direction. More likely for switch noise if its a cap. But a "brown glass" diode, or even resistor might be used too. Just swap it over, then try again. 

If it has one, adjustment of the switch position, or bending the arm some for better contact, might need to be done. Just don't pry against the sw housing with the arm.

can you post a photo of the old switch and brown thing?

I think you need to do both of the suggested fixes here.  Install the "brown thing" on the new switch, making sure that you get its orientation - which way it goes, as original.*  Also be careful when soldering it - it is easy to fry these things with an over-zealousness of the soldering gun.  Also make sure to check out and adjust the positioning of sensor, etc., I have seen slightly mis-alignments give intermittent results like you have.  

*I'm not certain whether this is a capacitor or a diode or a resistor without seeing pictures and a circuit diagram, but another possibility is that it failed and shorted out the switch, which would cause a cessation of chuffing like you had.  If you have a multi-meter, you can test it: if it has zero resistance in both directions it is bad, whatever it is.  (If it has zero resistance in one direction and a lot in another it's a good diode, a lot (near infinite) in both directions probably a cap, and the same resistance but not near infinite in both, a resistor.  

The "brown thing" is doubtless a ceramic capacitor, it probably looks a lot like this.

Thanks for your post everyone and John - that is exactly what it looks like.

MIKE