i had this problem. my printer is the lexmark x5470 (printer/ fax/ scanner/ copier combo with mem card slots on it). i expect this solution will work for all of you though.
i had installed the lexmark software and, ofcourse, it crashed everything.
here is what i did.
uninstall the stupid lexmark software. it doesn't work with leopard, because lexmark makes products with winblowz users in mind. this happens a lot and is the price we all pay for having superior systems. anyways..
i then went to the printer/ fax prefs and chose 'add printer'.
my printer was not in the drivers list, but there was a blue link below it for software update. i clicked that, and software update appeared. along with a quicktime update were new lexmark drivers. i guess by following the link from that location, software update looked for these drivers specifically.
i did the update, and restarted. you have to restart. the new drivers will not appear until you do.
now go and add the printer using apple's drivers.
after doing this, my printer worked fine and my pdf printed from preview with no problems.
hope this helps.