Family Medical leave Act

i currently live in new mexico.however i have worked for the usps for over 17 years. in 1996 i was diagnosed with carpel tunnel syndrome. this condition has become extremly pain since 11/99. as a result i had surgury for both carpel tunnel syndrome and decovain release in 1/2001. 10 days after surgery i return to work as a relief acting supervisor which involve very little of the action relate to the surgery. i have had to complete 2 flma applications for my employer. i have used only one day of flma leave of the most recent application.i was given a displinary discussion for the days i used under application one. now i am being told due to the fact i did not use any flma since 1/27/01 i will have to complete another flma application. I have been under medical care constatnly since 11/99 and complete light duty certification every 30 days.
what are my rights regarding refusing to complete another application?