Once installed, go to Apple (top left corner of menu bar) and select Software Update to make sure your computer is up to date.
AS STATED IN MY INQUIRY, I have already down-loaded and run both of these, as well as the "WirelessSetupAssistant_2.0.0_10.6orLater_forIntel".
"No updates available" was the response
Wireless, using the same network I had used with my iMac G5 (Power PC)
also tried to add the printer under "Print and Scan" options and I get:
"Can't install the software for the Lexmark S300-S400 Series because it is not currently available from the Software Update server."
Tried to use thru IPP & HP JetDirect Socket, without success.
Use:_field autopopulated with Generic PostScript Printer. Added the printer that way, but i would not print.
Deleted that device from the list and tried to add it again. This time it somehow found Driver Version: 11.2 without special action on my part.
Possibly the reason that it "Can't install the software for the Lexmark S300-S400 Series because it is not currently available from the Software Update server", was simply because the server was busy.
I have no other reasonable explanation.
BL: Can now print and scan.