Override JQuery Curvy Corners

Override JQuery Curvy Corners

I am using jquery curvy corners it works great everywhere but in IE7. I want to "de-activate" it but putting
  1.     -webkit-border-top-left-radius:0;
        -webkit-border-top-right-radius:0;
        -moz-border-radius:0 0 0 0;
        -khtml-border-radius:0 0 0 0;
        border-radius:0 0 0 0;



in the IE-specific style-sheet doesn't seem to work. I've looked in the code after the page is generated and it has
  1. class="main drawn hasCorners" jQuery1280509440617="3" jQuery1280509440570="337">
in the class on the generated html. I think I want to just take it out but how would I do that?

The page in question is http://www.4culture.org/test/ and it is the bottom set of tabs "Application, Workshops etc."
Is this enough information and did I post in the correct forum?
Thanks!