Heyho. 😊
I found a bug on 2.5 RC4:
When you activate a secret on a screen and put a secretflag (for instance flag 16 or 17) on layer 2, the changes are not shown by the overworldmap (when pressing the "map-button).
2.5 RC4 Overworldap doesn't show layers after secret
And this is a duplicate of the following thread:
http://armageddongames.net/showthread.php?93588-Map-But-%28R1%29
Coincidentally, it was first discovered in RC1.
I'm sorry, I didn't recognized that thread...
No problem, Rastael, thanks for reporting it!