Hey,

I really need your help. I bought Pathologic yesterday and it worked fine until now. Everytime I walk through the streets I am "kicked" back to the index screen as if my figure died But I checked the health and everything and it's ok, so ... do you know what to do? Is there a patch I can download?

Could you specify what time is it in the game? The point is that the main quest of the first day must be completed in order to move forward (if you play the first to characters). Otherwise you'll get FMV with voice-over like this:
"We have pinned our highest hopes on him - and he did not get ready for the encounter. The hair-devourer, the bone spirit, shabnakh stalked him, touched him and turned his blood into poisonus tar. Having devoured the body she delved into the depth of the steppe, reached the inner waters - and the pestilence swallowed this land"

which means - game over.

Other "tasks of the day" may be failed, and you will still be able to continue (though one of your adherents will be diseased)

I have the same problem as him. I'm in the first day at about 22:30. I was at the girl at the graveyard, and I'm heading to the man who is selling blood to buy some for the man who wanted to kill me.