My sould trap spell doesn't seem to work. I have an empty "soul trap" in my inventory ( I could have sworn they were called "soul gems", this is what I suspect is the problem.) and I've casted both the standard soul trap and a custom made one. It says "trap active" but when I kill the monster nothing happens.
I took a guess at that it may be a problem with not being patched properly, so I tried to re-install the patch. The patch wouldn't reinstall SO I reinstalled the whole game using the special installer for windows. This fixed the problem entirely so I'm assuming it was a patch problem.