I know it's been a while since you started this thread, but I am currently trying to get this working for my mom, who just recently upgraded to jaunty.
Here is the message I get after install the printer driver again:
It looks like the drivers don't "see" the newer packages.
The following packages have unmet dependencies:
cnijfilter-mp600: Depends: libglib1.2 (>= 1.2.0) but it is not installable
Depends: libxml1 (>= 1:1.8.14-3) but it is not installable
I will post when I get a solution.