I had the same problem and your solution worked. But........(seems like there's always a but).....this happened when I upgraded to Mac OS 10.5.4. When I went to the location mentioned in Libraries, I found 2 versions, #2 and #3 (ver6.01) When I run the new one, it shows me an empty printer list. I have a 1280. The older version, #2, still seems to work right.
When I go to run Print Center, which is where I seem to remember that you "find" the printers that you want to access, it "unexpectedly fails" before it opens.
Anyone encountered this or have any ideas?