Glitch - note repeating when key held down.

[nico88]

I bought a 73 key GS recently and discovered the E above middle C sometimes repeats itself when I strike it hard and keep the key held down.
I am assuming it is a rubber contact problem. Are all RH3 rubber contact strips the same ie, on Ebay someone is selling contact strips for Kronos 2, SV1, SP250 etc but doesn't list the Grandstage in the description.