I too found that my Olympus P10 failed on doing a fresh install of Leopard. However, I have found that patience is needed. If I print using the Apple supplied driver, the printer shows it is receiving the data and then the print starts approximately 4 minutes later. It seems as though the system is waiting for a timeout. Also, after successfully printing, the print is NOT removed from the print queue.
The P10 is on an Airport Express. I have yet to test it directly connected to my laptop's USB port.
I am also disgusted at Olympus's lack of support in not releasing a Leopard compatible driver, since I have been delighted with this printer. It's successfully delivered well over 400 prints for me, so far.