Cant print to a Phaser 7750 from Snow Leopard 10.6

I just upgraded from Tiger to Snow Leopard on a MacBook Pro with Intel Core duo. Since thta moment, I can't print to the phaser because the printer restarts by itself.
I tried using other computers with older OS versions and the printer is fine.
I also downloaded the latest driver for OS 10.6 from Xeron and tried to upgrade the firmware on my Phaser 7750 printer, from 5.02 to 5.06 but just could not do it.
Is there anything else I can do
Thank you for your help
Jaime Castillon
C+C STUDIO