Version:           kprinter 0.0.1 (using KDE KDE 3.2.1)
Installed from:    Compiled From Sources
Compiler:          gcc 2.96 
OS:                Linux

environnement :
 Mandrake Linux: 2.4.18-6mdk
 Qt: 3.3.0
 KDE: 3.2.0
 kprinter: 0.0.1
 cups: 1.1.14

a little application to test printer:

void tst_kdeprint::slotPrint()
{
   KPrinter printer;
   if( printer.setup( this ) )
   {
      printer.setDocName( "tst_kdeprint" );
      QPainter p;
      p.begin( &printer );
      p.drawText( 100, 100, 1000, 1000, Qt::AlignTop | Qt::AlignLeft, "Essai ..." );
      p.end();
      if( printer.outputToFile() )
      {
         char c[1024];
         sprintf( c, "cupsdoprint -P 'Imprimante' -J 'tst_kdeprint' -H 'localhost:631' "
            "-o ' PageSize=A4 copies=1 media=A4 multiple-document-handling=separate-documents-collated-copies orientation-requested=3' '%s'", printer.outputFileName().ascii() );
         printf( "commande: %s\n", c );
         fflush( stdout );
         system( c );
      }
   }
}

printing to ps file works fine, the command cupsdoprint ... is correctly executed ...
printing with CUPS doesn't work

added some trace to cupsdoprint ... here is what i obtained:
--------------------------------------------------------------
P: Imprimante
J: tst_kdeprint
H: localhost:631
o:  copies=1 multiple-document-handling=separate-documents-collated-copies orientation-requested=3
Processed options (n=3):
   copies = 1
   multiple-document-handling = separate-documents-collated-copies
   orientation-requested = 3
Files (1):
   /tmp/kde-ns/kdeprint_CvqOtQN1
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
ls al /tmp/kde-ns/kdeprint_CvqOtQN1 /home/ns/print.ps
-rw-rw-r--    1 ns       ns           9695 jun  6 09:47 /home/ns/print.ps
-rw-rw-r--    1 ns       ns           9684 jun  6 09:47 /tmp/kde-ns/kdeprint_CvqOtQN1
diff /tmp/kde-ns/kdeprint_CvqOtQN1 /home/ns/print.ps
2c2
< %%BoundingBox: 0 0 594 0                                             <-- ????????????
---
> %%BoundingBox: 0 0 594 842
5c5
< %%CreationDate: Sun Jun 6 09:47:57 2004
---
> %%CreationDate: Sun Jun 6 09:47:52 2004
99,101c99,101
< 0 0 translate
< % 210*0mm (portrait)                                                 <-- ????????????
< 0 0 translate 0.75 -0.75 scale/defM matrix CM d } d
---
> 36 24 translate
> % 184*280mm (portrait)
> 0 794.25 translate 0.75 -0.75 scale/defM matrix CM d } d