Jquery hover event doesn't work on IE7

Jquery hover event doesn't work on IE7

Hi guys,

I'm trying to add a simple growing effect to a div using jquery, i'd like to create a button that changes his dimentions on the over event of the mouse and turn back to the original dimensions once the mouse is out.

I've used the hover event and I've created 2 functions:
one for the growing effect used on the over status
and the other one for the reduce effect used on the out status.

In IE 7 I've got this error: the growing function is working but the reduction function is not working at all the error code on javascript it's only "Invalid property value".
Here some code:
       function makeBig(){
                $(this).animate({
                "opacity":"0.80",
                "width":"200px",
                "backgroundColor":"#FF6600"
                },500);
       }
       function makeSmall(){
                $(this).animate({
                "opacity":"0.50",
                "width":"150px",
                "backgroundColor":"#FFFFFF"
                },500);
       }
       $("#home").hover(makeBig,makeSmall);


this code is working fine on FF and Chrome!
WTF?