gothrall: Out of curiosity, what do you guys have in the <TurnDuration> element in the \Data\Manager\Rule.xml file around line 89?
I have only the Steam version and it looks like this:
<TT>
<Blitz>
<TurnDuration>(480,360,240,180,120,40)</TurnDuration>
</Blitz>
<Classic>
<TurnDuration>(240,120,40)</TurnDuration> </Classic>
<NbTurn>16</NbTurn>
</TT>
It's a nice thought but don't bother digging around the other files. Before I swapped the executable I had already tried replacing ever other single file in the GOG version with the Steam version's equivalent. If that had been successful at some point it would have been great since none of those swaps would have required dealing with Valve's DRM. It hadn't worked, unfortunately, so the only conclusion left was that whatever bug it was, it must be in GOG's executable.