Ok seems that I've solved my problem, at least. Here are some pictures to show you what I did.
http://i22.photobucket.com/albums/b324/MathiasSerau/Fuser.jpg
This picture shows the cause of the problem. Turns out, it was as simple as the hole from the black piece not being lined up with the whole from the metal piece. (This is the fuser, by the way) All it took was me unscrewing the metal piece (four screws on the bottom of it), and then refitting it so that the holes lined up. I didn't have to force it at all; I merely set that in first, and everything else lined up perfectly afterward. Be warned, though, that there is a fifth screw that holds this spring-like thing on the side, you do have to unscrew that to remove the metal piece. I made the mistake of doing this without knowing what it was, and when I removed the metal piece the spring thing went flying off. Didn't break, just a warning!
http://i22.photobucket.com/albums/b324/MathiasSerau/FuserJam.jpg
This picture, albeit really blurry, shows a closeup of the rollers that are mounted near the black piece. The arrow shows that the paper, when going through the fuser while the black piece was pushed too far up by the metal piece, would jam underneath the black piece, which was apparently the source of my problem.
After fixing the metal piece how it should be, I was able to manually roll a piece of paper through the fuser by putting it between the rollers and turning the gear by hand. So, I put the printer back together and everything appears to running normally.
Let me know if this helps you. I have a feeling that HP is simply retarded, because BOTH MY NEW AND OLD FUSER HAD THIS SAME PROBLEM! After I discovered this on my new fuser, I looked at the old one and sure enough, the pieces were not aligned properly. Bad construction?
