Well, I did some further testing and even after reinstallation, this bug continued to occur. I noticed furthermore that the game only crashes when my customized main character is overburdened past his maximum weight threshold. When the Death Knight is overburdened in such a way, the normal game functions occur and the game does not crash. Moreover, this occurs both within and without the dungeon, so it's not that either.
The problem is isolated on the main character becoming overburdened, not the Death Knight. Raze, did you test overburdening the character as well, not just the Death Knight? You may yield different results, though I doubt it.
I'm assuming this is a problem with a file in the game, something that's either missing or corrupted or misplaced, but every time I verify the integrity of the game cache, it all checks out. I'm too oblivious in this field to go manually searching for the issue, either, not to mention I don't have the programs to do so.
