Post XP SP3: commandline print install

We have about 10 clients which print to a CUPS server.
Since XP SP3 the automated printer install doesn't work correctly anymore,
whereas the same script works in SP2.
Though in both SP2 and SP3 the printer is flagged as offline SP2 actually
sends the printjob whereas SP3 sometimes does but mostly just time-outs.

The printer is installed from the print.bat startup script as following:
"%WINDIR%\System32\RUNDLL32.EXE" printui.dll,PrintUIEntry /b "%BASENAME%"
/if /f "%INF%" /u /r "%URL%" /m "%STRING%"

where:
Basename: Archibald (Samsung ML-4551ND)
INF: Archibald.inf
URL: http://print/printers/Archibald
String: Archibald

Funny thing is, when using the Add Printer Wizard it actually works but
since we have multiple clients we'd rather deploy the printer that install it
manually on every system.

Does anyone have a clue how this is to be done?