Saved game failed to load

[Heinkel]

I´ve received some mails from my PBEM opponents. They can´t load their turns. What causes this problem?
What is really confusing, is that last time I had this problem some months ago, after that there was no problem. But almost all games that I played 11th-12th February were ruined, and refused to load.
Are there any other way to continue gaming, than play last turn again?

[Supervisor]

Many times what happens is that the 2 players are using different version OOB's which causes that failure. Ver 7.1 is due out any day and correct other save game issue, the PBEM problem may also get cured. By both players have to use identical games to get it to work.

[Heinkel]

Correction:

I got mail today. ALL my battles that are played in 12th february refused to load. Weird, because playing turn again fixed this, and game worked.
All Oob´s are same, versions are same.

[Heinkel]

Now I thought one thing that could cause my problem:
I play two player campaign (from solitaire play- option), and when I´ve played it, I go to PBEM and play other turns. I´ve heard something that playing PBEM and solitaire games at the same time (should I exit from game and start again for PBEM turns) messes some files. Is this true?