Actually, it probably is; there's a lucky coincidence that there's a slot in the fascia that lines up with the unbent lip, and all the unbent ones I've seen allow the empeg to slide all the way in anyway.

I'd suspect the wiring inside the sled's connector. Apparently many of the MkIIa sleds' connectors' pins weren't crimped well. I'd take it apart and try to fix that wiring. There's a FAQ that details how to take it apart and solder the wires to the pins.