Dream,
Has your doctor considered the possibility that the Lupron you're on now may have failed to control the generation of testosterone and that he should consider another drug? For many men, some HT drugs just don't seem to work while others are very effective. It's not surprising to me that your PSA is rising if your testosterone is going up so quickly. A rapid rise in testosterone levels could be an indication of a more aggressive form of cancer. Does your doctor measure dihydrotestosterone? It is much more powerful in stimulating prostate growth than testosterone but many doctors don't routinely measure it and and it may well be rising too. From what you have described, the rapid rise in your testosterone level may be a strong indicator that Lupron isn't working for you.
It would be interesting to plot the times you started and stopped Casodex and Lupron against your testosterone levels and PSA. From the data in your signature, it looks as if you reached the lowest PSA about 12-15 months after your IMRT which is reasonable. Frequently following radiation there is a PSA bounce at about this point before PSA levels decline again to some low level nadir. If you stopped taking Casodex about that time and switched to Lupron and your testosterone and PSAs began to rise it would make me very suspicious about the efficacy of the Lupron in your situation. You may wish to discuss with your medical team an alternative mix of drugs in your androgen therapy.
I'm certainly not an expert in this area but I studied it during my research before treatment. Hope you get some answers soon.