Tulio
the spring peter is discussing is here ...
try reading this blog article ...
http://cjeastwd.blogspot.com/2009/11/micro-43-om-adaptors.html
the points it makes with reference to the OM lens seating on the adaptor are precisely the same points of the adaptor seating on the camera
in particular look at this image carefully
click on it in the blog article (or any of the images actually) for a larger view
examine your lens and look at the rear of the lens (the mount) carefully, perhaps you will see the flanges being discussed. I do not know if you are a native english speaker, so if not, if your language is Spanish, try these words
noun
1. ceja
2. pestaña
3. reborde
4. brida
5. borde
I don't speak spanish, so I can not comment on the relevence of them.
If the answers I provide are insufficient for your understanding, please ask specific questions related to that reply and I will do my best to rephrase, but as I have gone to the trouble to reply it means that I am trying to help you.