Alright, so curing vampirism brought me back to having a khajiit head on an imperial body, but with the headgear placement still wrong. Ugh
Here, go to the page I have linked in this comment and report it as a "graphical, possibly script-related bug," and describe everything that has been happening. It should help spread the awareness of the bug for Bethesda to find it, and possibly inspire others to see if it's happening in their games as well.http://www.gamesas.com/topic/1389814-dawnguard-bug-list-1/
I would personally like to see this bug get fixed.
Edit: Fixed so you go to page one rather than page five.
Update: I left a comment on the thread in the link describing your problems so that it will garner more attention from people on the forums. I felt that the sooner the bug gains attention, the better. I certainly don't want this bug to happen to me or anyone else who doesn't want it happening.