Yah, something changed recently and 'broke' steam cRPG detection. It used to detect warband being launched when you played cRPG. Now it doesn't anymore.
As a temporary work around i use the 'add as a non-steam game' trick i mentioned earlier, but it doesn't add any more 'time played' and achievements and such for warband on your steam profile. However, it does show i'm playing cRPG on my friends list when i do, so that at least is nice.
Dunno how to fix that. Open to any suggestions. Anyone got an idea?