Basically, the Print Center sucks.
Download "Cocktail" (get it at
www.versiontracker.com).
Run it.
Restart.
Delete printer drivers that you don't need.
Reinstall the drivers you do need.
I have issues with one of my two printers where if I don't manually launch the Print Center prior to sending a print command to my Epson printer, the printer will fail to print or will print a big black page.
You might also try "Print Center Repair" (get it at
www.versiontracker.com) as the other poster suggested.
Good luck!