Canon BJ S100SP and BC20 Cartridge

We have a Canon BJ S100SP printer that works fine with the Canon BC21E print-head with BCI21BK and BCI21C cartridges installed (combined black and colour) but won't print when a BC20 black cartridge is installed. The print queue just goes to printing stopped and will not start until the BC20 cartridge is removed. Used to work fine with an old iMac and OS 9.2 but refuses to work with the BC20 cartridge installed on a new Mac Mini and OS 10.4.5 Is this a problem with the OS or with the printer?

G5 Xserve, G4 Xserve, Xraid, PB G4 15 Mac OS X (10.4.6) SysAdmin