Problem in converting a .ps in .pdf with multiple images of the same pixmap

[vratojr]

Hello,
this is the very simple program I wrote:

QPainter paint(PSPrinter);
QPixmap sigmaPixmap("Immagini/sigma.xpm");
for(int i=1;i<5;i++) paint.drawPixmap(QPointF(10*i,10),sigmaPixmap);

QPainter paint(PSPrinter);
QPixmap sigmaPixmap("Immagini/sigma.xpm");
for(int i=1;i<5;i++) paint.drawPixmap(QPointF(10*i,10),sigmaPixmap);

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If I use this code to print on screen, I have no problem.
if I use it to print on .ps,no problem.

The problem arises when I try to convert the ps to pdf usint "gs",this is the error I get:
convert: Delegate failed `"gs" -q -dBATCH -dSAFER -dMaxBitmap=500000000 -dNOPAUSE -dAlignToPixels=0 -sDEVICE="pdfwrite" -sOutputFile="%o" -f"%i"'.

Please,don't tell me to print directly in pdf! I need to print first on ps...

I also tryed to create a Vector of pixmap like this:

QVector<QPixmap> pix(5,sigmaPixmap);
for(int i=1;i<5;i++) paint2.drawPixmap(QPointF(10*i,10),pix[i]);

QVector<QPixmap> pix(5,sigmaPixmap);
for(int i=1;i<5;i++) paint2.drawPixmap(QPointF(10*i,10),pix[i]);

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but the result is the same.

What do you think?

thanks!