Make sure that while you are bleeding the brakes, you open up the master cylinder cover envery now and again and keep the fluid level high. Also, when you think you are done bleeding the brakes, and have put away the tools, open the cover one last time.
Brake bleeding creates a vacuum in the master cylinder, and if you don't release the vacuum, the brakes won't pump up. I found this out with a friend's FZR600. We changed the pads, had decent brake feel, bled the brades, and all the feel was gone. Opened the cover, added fluid, put the cover back on, and suddenly the brakes were back. Bled them again, and it went bye-bye one more time.
Finaly realized what was happening, and took the cover off, put it back on, and his brakes were fine ever since.
Also, another good way to make sure every last air bubble is removed is to squeeze the brake lever, and tie it to the handlebar and leave it overnight. Come back, open the bleeder, and get that last bit of air out. Sometimes it takes the smaller air bubbles alot more time to travel through the compressed fluid. Leaving the brakes activated overnight gives them time to get into the caliper.
BC.