Is the module css3pie necessary to fix ie? How can i simplify?

I'm dealing with the ie compatibility problem these days,and I found a great file to fix it ,that is PIE.htc file,For noe ,I assume you know the usage of this file ,
here is the problem ,why can't we just add one line in the css file of our theme to fix that problem?Just like below
* {behavior:url(therightplace/PIE.htc)}
when i put this line in my css file ,it doesn't work,neither the border-radius nor box-shadow.(I know that the linear gradient effect need another code),who can tell me the reason
And the css3pie module is just not as good as we want.So much work need to do with this module ,

If anyone find a better way to fix this problem,please say it loud ,thanks!