current-menu-item not working with custom post type

Solved!
The problem was in the plugins settings …
To fix this problem go to:
Events(Left Admin Sidebar) -> Settings -> Pages -> Event Categories
and set “Override with Formats?” to NO
Thats it … I hope this information to be useful for others, and save them a lot of time, which they coud use for a walk, drinking beer and whatever they want. 😉
Cheers!