32bit PNGs not transparent

ive created some f**kin PNGs in Fireworks and set the background(canvas) to transparent.. when opening in windows and other programs they really are transparent, but in internet explorer theire not.. they get the same background color as one of the tables on my site.. in netscape(and probably mozilla too) the are transparent, but the 32bit alpha effects(like drop shadow and things like that) doesnt work there..

any of you have a clue abou how to do this?

yes i have to use pngs..(i guess some of you will ask about that if i dont write it)

maddog said it was disabled in ie.. what a stupid f**king thing to do of microsoft..

i agree.. PNG is the best! actually pngs can get much smaller than both gif and jpg.. but with this f**king transparent thing in ie i cant use them to what i had planned..