I don't know what would cause the character to level up like that at the start, but I have heard of the problem before. In fact, I remembered it was Soil who had had that problem.
He said: "Now when I start my game, I get the sound of levelling multiple times, and indeed, I insta-levelled to level 30." Is that what's happening to you guys?
It seems to be caused by something being added into module_troops in the wrong place (like if you added a troop in the middle of the list rather than at the end, maybe - new troops can only be added at the bottom, just as new items can only be added at the bottom of module_items or it gets all mucked up).
His thread on the problem might help you solve it.
Here it is: http://forums.taleworlds.com/index.php/topic,50971.msg1315472.html#msg1315472
Or it might be, since you level up to 33, that you have somehow designed your character to be a Worthy Master in the Masonic Lodge?
If you've added troops in the wrong place in module-troops, it could be that.