I have the same printer and the drivers
are lacking. First, get the latest ones from HP. They just released new ones not too long ago. Second, RTFM. These drivers suck in the way that issues that can arise, are somewhat covered in the documentation.
One such issue they warn against is that if the drivers are going to be used in OS 9 and X, to install in OS X
first.
So, if after reading the docs and a clean install of the new drivers, there are still problems, call the HP support line, free, but not an 800 #, and they will hook you right up. They will also likely tell you that these drivers are not the best and will be getting better in subsequent releases. I have used tech support there and they will help you until the problem is fixed. I have had very good expereinces with them.
I have them printing fast from a 600mhz , 300hnz and 466mhz iBooks. So it can be done. There just might be some HP voodoo you need to do.
Good luck.