Please somebody could help me ? .. i will become crazy :p

I done a new website and i would like use some css3 (border radius, shadow, gradient etc..)
Look my website to firefox you will see:
http://www.cas-p.net

well so i use PIE in a css style for IE
but it doesent work at all.

But if i use the IE9.js or IE8.Js of the IE7project

Well all css3 work, but for IE8 only.
And the bad news: IE9.JS make some really straneg bug on IE7 browser.. all my font become times except the font inside a span...

But if i dont use the IE.js well PIE dosent work ....
I understand nothing...

I really would like to have the css3 attribute, at least on IE8
But if i choose this option my website become really ugly on IE7 its not possible

...
i reexplain my problem more simply:

Hi, i have some trouble to use PIE with IE7 ...
Its works very well with IE 8 but nothing on other version ..
Anybody knows where it could come from ? or what should i change i my code ?

Nobody has this problem before me ?

(sorry for my poor english)