The problem with Amber (S.T.A.L.K.E.R.: Clear Sky)

The scientist took the documents, went to the group of Lefties. First time went to the amber, I slammed the zombies on the roof after the group Left-hander did it. Load the save game, with the moment came to scientist (to dialogue) - give zhokumentov, go to Lefty's and then all the circus begins. Every time they behave in different ways, ten times to beat:
1. After Lefty gives the command head one Stalker remains behind the fence, well worth it. All the others then crowded with boxes and not moving on.
2. One or two stalkers turn around and go to the lab there and hang out. Then the rest of the plant does not go.
3. If still climbed over the fence, then they go to the place near the fence of the box, but one Stalker goes back and goes through the fence, or hangs on his haunches beside the corpse zombie. All the other stick.
3. Is that all going near the site of penetration of the plant and standing around, looking at each other. It is worth a shot as they shout in unison"the Enemy!, begin to look around the sides, but the boxes over the fence do not go.
4. I climb over one, kill all the zombies, go to the roof - stalkers or continue to stick behind a fence, or one or two still come after him, and begin to walk around the factory and to search the corpses. After a search they all crash into one and begin to search it endlessly.

In the place where my documents are, but I haven't taken them to the scientist had two saves with a difference of half a day (time zones), and the other loaded - the result is the same - stalkers Lefties are not going to turn off the tap.
Decided to replay again and instead to give the documents to the scientist - gone to other locations, wander - into the garbage, Agroprom, Dark valley. Then returned to amber, bring the documents, go to Lefty's - everything goes on the same scenario.
Frankly, I'm sick of already.

How to make stalkers Lefties stop rebate?