For anyone interested in hormone therapy, I suggest reading Dr Myers book, "Beating Prostate Cancer : Hormone Therapy & Diet".
A few points discuss with your doctor in the meantime: A criteria in PSA rise is 3 higher peaks in the numbers. Measuring of Testosterone and Dihydrotestosterone levels should be done to gauge whether the medication is doing what it's supposed to be doing.
Some people react differently to the various medications. There could be a better response with an alternative product &/or the addition of Casodex.
A friend who was diagnosed in late 2005 has maintained a PSA of 1 and more recently slightly less with Eligard use.
If you havn't already done so, it would be worth consulting someone expert in hormone treatments, like Dr Myers, Dr Dattoli, or Compassionate Oncology.