Flash Pro 5.5 ios universal app scaling = bad

Hey everybody I'm currently working on a game that is all bitmaps.  I want to make the game with universal support and wondering what a good method for scaling the bitmaps is?  When I publish for iphone and ipad it scales and if I give it a little extra off the stage to fit the aspect that works but the scaled graphics look pretty bad.

If I turn on smoothing for all the bitmaps it looks much better but that talkes a performance hit on the iPad.  For whatever reason even with bitmap smoothing turned on the standard iphone resolution runs smooth as silk.  So it seems to be perfect for 480x320 users to smooth but iPad suffers and I am assuming 960x640 users would suffer as well.

I know typically universal apps for ios use multiple bitmap images depending on the device and would like to do that if possible.  I read it is possible in Flex or Flash Builder to load multiple dpi resolutions but I do not see any way to do this with Flash 5.5.

I would really like to make my game universal and really appreciate any help.

Thank you.