Problem with PrintJob and default background

Hello, I have problem with PrintJob - printing to pdf.

I want print some bitmaps with transparency and vectors.

I checked all options and still have grey background under bitmaps and vectors. This is stage background color.

var pj:PrintJob = new PrintJob();
var sheets:MovieClip;// = new Sprite();
var options:PrintJobOptions = new PrintJobOptions();
options.printAsBitmap = false;
var dodd:MovieClip = new MovieClip();
stage.addChild(dodd);
var pagesToPrint:uint = 0;
if (pj.start()) {
    for (var i:int = 0; i < pages.length; i++)
    {
        sheets = new MovieClip();
        //sheets.graphics.beginFill(0xFF0000, 0);
        //sheets.graphics.beginBitmapFill(pages.getChildAt(0).bitmapData, null, false, true);
        /*sheets.graphics.lineStyle(0,0,0);
        sheets.graphics.drawRect(0, 0, pj.pageWidth, pj.pageHeight);
        sheets.graphics.endFill();*/
        sheets.addChild(pages);
        dodd.addChild(sheets);
        try {
            pj.addPage(sheets, new Rectangle(0, 0, pj.pageWidth, pj.pageHeight) , options);
            pagesToPrint++;
        }
        catch(e:Error) {
            // do nothing
        }
    }
    if(pagesToPrint > 0) {
        pj.send();
    }
   
    while(dodd.numChildren>0){
        dodd.removeChildAt(0);
    }
    stage.removeChild(dodd);
    dodd = null;
   
}