Picture quality issue

1

why exporting fla with flash 7 player imported images are loaded with good quality, but with flash 8 player images are with bad quality? what’s the problem?

var layouts = new XML();
layouts.ignoreWhite = true;
layouts.load("xmlphoto.xml");
layouts.onLoad = function (labs)
{
    var _m2 = this;
    if (labs)
    {
        var _m1 = 0;
        while (_m1 < _m2.firstChild.childNodes.length)
        {
            var _m3 = maska.attachMovie("article_mc", "article" + _m1, _m1 + 2, {id: _m1, num: _m1});
            _m3.mcBlank.loadMovie(this.firstChild.childNodes[_m1].attributes.thmb);
			
	


	   
			_m3._y = _m1*170;
           
            _m1++;
        } 
      
    } 
};