frameline problem M6 & Heliar 75/2.5

[Peter S]

Ladies and gentlemen,

Funny problem here. When I use my Heliar 75/2.5 on my M6 it does not bring up the 50/75 framelines. My Summicron 50/2 brings up the right framelines and so does the Elmarit 90/2.8; I checked the LTM adapter and it says 50/75. Went to a Leica dealer and they confirmed that there is nothing wrong with my camera. Any clues/suggestions?

Thanks

Peter