Damage to save files (Serious Sam 2)

After the passage of the 1-6 level (where we save the shaman), begins 1-7 because of which this problem appears
When you log in, there are reports of file damage
The problem does not disappear even after passing several levels (the 5 levels still passed)
Who came across it and how did you deal with it?
Do the idea to pass the game in one breath at the weekend, starting in the early morning and well prepared, if you can not fix the problem, try?