I was doing something similar to what Guy Perfect is doing. I was doing collision response pretty much exactly as shown in fig. 8, but this caused the player to slide down slopes since every frame I increase the y velocity to mimic gravity. So, I ended up treating every slope as if it was flat when doing the velocity calculation. Also he (I’m assuming Guy Perfect is a guy) didn’t talk about handling multiple collisions. You can’t just handle them one at a time because then its possible that the player will still be colliding with an object after all collisions have been handled.
Oh, and if you’re interested, I posted my engine here http://z3.invisionfree.com/MP2D/index.php?showtopic=2537. The most recent version is the one hosted on 110mb not on rapidshare.
Also, the zip you linked to is password protected.
edit
Now that I think about it, the thing I said about multiple collisions wouldn’t be a problem if when you were moving the player after a collision you did so according to the players velocity. As in if the player was moving at at 45 degree angle up and to the right and then collided with something, then you move the player down and to the left at a 45 degree angle to correct the collision.