OK...
It would help greatly if you could describe when (time stamps and all) and how the extra packs appear. It's not normal, and probably lag-induced. I'd suspect if it were a system-wide thing, everyone would be experiencing it.
Killing your ox won't do anything really. The ox itself is created on login and destroyed when you log out. In effect, each time you log in, you get a new ox. Your ox pack is linked to the database. This is the only thing that's really persistent about the whole thing, and it gets created and destroyed in-game by taking it off/putting it on the ox.
Killing your ox and letting you buy a new one would break the association between you and your current ox pack, but if there is some other problem that is causing duplications, then it will reappear.
What we'd like to see is the steps it takes to reproduce this.
I'd suggest if you wish to try and reproduce this, that you do so after the next server reset. Starting when there's already several copies of your ox pack doesn't necessarily give a good test.