1st Gen R52 Cooper Convertible Sunroof opens, but goes no further

On Tuesday I took my cabrio to the dealer for this problem, and a leaky upper motor mount. The micro-switch under the rear parcel shelf is fully engaged by the shelf, but the top will not go past the open sunroof position. Pressing the button yields nothing: no motor noise and no little red flashing light on the button. Anyone else have this issue? I'll report when I'm told of the root cause.

Update: Got a call today from the service writer at the dealership. They had to order a switch...not the microswitch and not the control switch. I guess I'll get the part number when I get the car back next week.