Cos - Not so, I am undertaking the FAA IR and my FAA PPL is issued on the back of my JAA PPL, it is therefore subject to my UK licence restrictions.
This taken from the FAA website RE foreign pilots:
When a U.S. pilot certificate is issued under FAR 61.75, it will include all the ratings (including large aircraft type ratings) that the applicant is qualified for on his foreign pilot certificate except for the instrument rating. If a foreign pilot wishes to obtain a U.S. certificate under FAR 61.75 and include instrument privileges that he may have on his foreign certificate, he must take a written (computer) knowledge test to show familiarity with our instrument rules of flight. This test is called the Instrument Foreign Pilot (IFP) test. Also, any limitations that appear on the foreign pilot certificate are limitations that apply to the U.S. certificate that is obtained under FAR 61.75. For example, some foreign aviation authorities do not allow night flying. That means a U.S. certificate issued on the basis of that certificate could not be used at night in the U.S. Also, some countries issue pilot certificates valid for the particular type aircraft the applicant used when tested by the foreign aviation authority. The foreign pilot in that situation would be limited to the same type aircraft on his U.S. pilot certificate issued under FAR 61.75. Restrictions cannot be removed by any pilot training in the U.S. For example, if a U.S pilot certificate is issued on the basis of a foreign pilot certificate that restricts night operations, training at night in the U.S. will not provide night flying privileges in the U.S. when exercising the flying privileges of the U.S. pilot certificate issued under FAR 61.75.
The holder of a U.S. pilot certificate issued under FAR 61.75 can qualify and be tested for additional ratings by complying with all of the U.S. certification requirements for that particular rating. These additional ratings will be added to the holders certificate with a notation in parenthesis, "US Test Passed".