Question about importing bitmaps into Flash MX 2004

I am working on a slide show, and well the buttons and all work, but I am importing bitmaps(png) into the stage, and when I play the slideshow in IE then the images look a bit ragged. I went into the bitmap properties and changed it from jpg, to png, but still get the same effect.
The photos are 454 x 288 at 32 bits per pixel and I have it to allow smoothing.

Looking for a bit of advice on fixing this...

Thanx