I have been fighting with some mates for several days now and I've come to a dead end. I don't know what else to try, so I figure I would ask you folks. I am new to Solidworks and I'm trying to learn, but this has me completely stumped.

I have an open topped box with angled walls. I am trying to mate all of the walls to the floor. Each wall is at a different angle from every other wall. I've made planes and cuts that should match up, but they simply won't mate and I don't know why.

For example, the left side wall will not made to the door AND the floor at the same time. It will mate one way or another, but not both. I don't quite know why. I've tried changing up the cuts, and I've made them match to the angle, but it simply won't mate. If anyone can shed some light on what I'm doing wrong, I would really appreciate it. I am having a similar problem with the right side wall. I haven't even tackled the back wall yet, but I imagine it will be easier to resolve, since it's a far more simple wall and set of mates than the others, due to the angle of the door.

The door is not intended to move, BTW. I am attaching the files I'm working with. This was really an experiment in creating a working assembly out of separate pieces, but it's turned in to a nightmare. I realize some of the parts/cuts/angles are kind of weird at the moment, but that was from my experimentation trying to figure out what's broken (and not having any luck) - I really wish Solidworks would tell you WHY it is refusing to mate.

Any help with this would be greatly appreciated. I would really like to know how to avoid this type of problem in the future.