Don't worry, I have ammended it.
No more problems since the next release of the Mission Pro Combo (sorry, it will be only for 4.101).
It was a stupid, very ridiculous way it loaded the "regional" settings and so determines if the .properties file will be a _ru.properties or not. The way it checked that was different in different parts of the game. But you know, theorically in Russia it works always OK.
Regards,
Pablo