Printer/Scanner Sharing with Time Capsule

I have a Macbook Pro (Aluminum), a 1TB Time Capsule, a HP Officejet 6500 Printer/Fax, and an iMac. The Officejet (printing and scanning) is shared through the Time Capsule's wireless network. On my Macbook Pro, I can print and scan wirelessly. Under my print & fax settings in system preferences there are TWO tabs at the top of the window, one says Print one says Scan. But this is only on the Macbook Pro. On the iMac, when I go to the Officejet in print & fax settings, there are no tabs at the top, and I can only print wirelessly. There is no scan option. This puzzles me because both computers are operating on the same OS. I tried software updating, and made sure the right drivers were installed, but to no avail.

Just to clarify, scanning on the iMac is the only problem. Everything else is fine.

Any help or information would be appreciated.