I thought this deserved its own post so I am re-posting Gunny's remarks with a more appropriate title.
Chukar had a very interesting problem. To fix it we ended up:
1. going to Steam "Library" - right mouse clicking "Il-2 Sturmovik:Cliffs of Dover" and selecting properties.
2. After the properties window comes up - then select the tab "LOCAL FILES"
3. Finally select "VERIFY INTEGRITY OF GAME CACHE..."
Chukar found that he was missing a file - which the Steam routine replaced and then "presto" - it all worked.
