I play on wii so this might not be possible but i found a different way you can do it. Its a bit slower but its much easier. For lab 4 once you get out of the door you go to the right wall jump on the thing outcropping from the wall that you can stand on stand on it then jump off and web jump across to the end. Once your at the end instead of going the way you would normally go you go right next to the white wall at the end and you go into the fall plane. If you have only web jumped there and have not touched any ground you should get out of bounds and then hold forward and jump when being pulled over to the place you last stood if you do it right you should be out of bounds and you beat the section. Its slower but it works. Then for lab 3 once the doors open to the place where you need to save the scientists. Go to the glass wall on the right that only has spider emblems in it. you break the glass and get in then you stand at the back of the room where the right spider emblem is. You then web jump out without touching the ground. Then you hit the fall plane and you hold the joystick in the direction of the door you cam from you should be out of bounds the you can web swing to the end and beat that portion of the level.
