It looks like game does not save high scores for skirmishes. To resolve this problem latest official patch from 2013 needs to be applied. Patch can be downloaded from Gamers Hell:
http://www.gamershell.com/download_100085.shtml
I know that this is a minor issue, but it would be great if GOG could update their build of Stronghold Crusader to the latest version.

Agreed... in the middle of an intense 3 v 5 and would've loved to look back on it :3