i saw tis at the other forum, maybe can help u, btw i had no problem in my 1st time trying though:I did it, i found a way to continue the mission !
If someone is still stuck after the cobra leave Chapoi, try this :
follow the road to the east of Chapoi (when you look at the map there is a green spot of friendly territory to the east, you go that way), you will meet a M113 waiting on the road and it seem to be the problem, since he is not moving the mission is stuck !
So, what i did is throw some grenades at him !
I throw a grenade and wait, nothing happen, not even a message telling me to cease fire !
Then i throw a second grenade, then the M113 react, moving just a little, so i wait and it take less than 30 seconds before i received a message saying that we should go seize Chapoi and that we would received support from the east (the M113), then the M113 drive at full speed to Chapoi
All you have to do is run back in formation, for me i didn't have time to get in formation since there was nothing left in town and the mission end as soon as the M113 arrived in Chapoi
Hope it help !