I have an ip5300, which the ip4500 is the replacement for...
I recently tried to use the Think+ inks from choice, having swapped the chip over from the original Canon ink, and it just wouldn't work.
(Changing the chip over was very easy)
I rang choice for advice and was told that the chips that are supplied with the ink that comes with the printer, wont work! Apparrently the "supplied with printer" inks are slightly different. You have to buy genuine Canon inks in the first place, and then use the chips from these on the Think+ inks.
I presume this to be the same with the ip4500. I would suggest you call Choice to have them confirm this, or otherwise.