Also, in some states (CA and PA comes to mind), state regulations states that if you are licensed by the board of osteopathic medicine, you must identify yourself as a DO either by having DO after your name, or using the title "osteopathic physician" or "osteopathic physician and surgeon"
Now since this offshore MD is worthless in terms of getting licensure, you'll still need to use that DO degree.
I think in the state of Kansas (not sure of exact state), there was an appeals court ruling affirming a state medical board decision to prevent a local dentist (oral surgeon) from using the MD degree he got from this same offshore medical school since this is considered misrepresentation.
The lesson in all this: Once a DO, always a DO.
Edit: Addenum
The court case is State of Kansas, ex el State Board of Healing Arts v Steven L. Thomas
http://www.dentalwatch.org/reg/thomas.html
http://www.ama-assn.org/amednews/2004/10/18/prl21018.htm
And the Pennsylvania code
§ 25.212. Professional advertising.
(b) Advertising, letterhead, publications or transmissions shall designate or indicate the licensees school of medical practice by the term D.O., doctor of osteopathy, osteopathic physician or osteopathic physician and surgeon.
Authority
The provisions of this § 25.212 issued under section 16 of the Osteopathic Medical Practice Act (63 P.S. § 271.16); and section 902(b) of the Health Care Services Malpractice Act (40 P. S. § 1301.902(b)).
And the California code
§1685. Display of Name and Earned Degree.
(b) Any licensee of the Board shall designate himself by his earned degree D.O., and/or the term Osteopathic Physician and Surgeon, and shall prominently display this designation on all printed materials employed in his practice relating to his licensed function as a physician and surgeon. A D.O. licensed by the Board shall not use the term M.D.
Authority cited: Osteopathic Act (Initiative Measure, Stats. 1923, p. xciii), Section 1; and Section 3600-1, Business and Professions Code. Reference: Sections 2275, 2276, 2452 and 3600-2, Business and Professions Code.