@mattbfg - A couple of tips on Pavlov House. When you get to the 4 mins left. Go to the back and to the left of the floor where you destroyed the 2nd tank. There will be a room that has almost no floor on it. Jump to the other side of the room, go prone and keep aiming at the door. Technicallly, enemies could also come from the porch there, but I played the level 3 times and everytime the enemy would just stand there.
When the 4 min are up, just wait for your friends to kill all the enemies. More of them will come to attack you, so just be careful not to reload at the wrong time. Also, there is a chance that the guy at the porch will actually try to kill you, so be aware.
And about the checkpoint, it wont save if you have less than 50% health.
Hoepe it helps.









