Are you zipping the file when you send it? I've had/seen problems with zipped .sav files when they are unzipped, at least in Succession Games I've played. Especially if one is using WinZip (or WinRAR), and the other is depending on Win XP's built-in zip software. I've been sending unzipped saves for PBEM, C3C's internal compression seems pretty good, the zip software rarely compacts it more than 5-10% anyway, and it's one less chance for problems.
If you're not zipping it, I'm not sure what the problem might be. Obviously, everyone should be at Patch Version 1.22. Do you have any different flags set in your .INI file, (Like NoAIPatrol=0) or something? Just guessing on that part. Don't know what else to check.