I have a problem.  One of my PBW games no longer lets me play.  Every time I try to start the game to play my turn, I get the following (paraphrased) error message:
Data files currently used do not match the files used when this game was started.  Check with your host to get the correct data files.
Problem is, I haven't changed any of the datta files.  I'm the only one with the problem, so it must be on my 'puter somewhere, but.....  But I didn't change anything!!!  It's only turn 8, so the AI is probably really starting to hurt me now (it's run two turns now).  If I can't get this fixed by turn 10, I'm going to withdraw and let someone else try to fix the AI's mess.  But I like this game, and I don't want to quit it (good starting position  

.
Any help at all would be appreciated.
I tried re-downloading the turns.  no good.
I tried running it without the mod picker (the games in it's own mod to keep ai-less shipsets out of solo games).  No go.
Help!!!