Run the software that is included with the printer, or dl from canon.com. Should have a routine that can clean the printhead. If that doesn't work, you will probably have to buy a new one. (printhead, that is)
Thanks for your replies and suggestions. I tried the HOT water thing and then I tried the q-tip alcohol cleaning, but no luck. Looks like I'll have to replace the printhead, or find a new printer. Thanks.