jquery: class="ui-corner-all" is not working with IE

jquery: class="ui-corner-all" is not working with IE

jquery-ui-1.7.2.custom.css

in this file following styles is there?
but it working nice without IE...

/* Misc visuals
----------------------------------*/
/* Corner radius */

.ui-corner-bl { -moz-border-radius-bottomleft: 4px; -webkit-border-bottom-left-radius: 4px; }
.ui-corner-left { -moz-border-radius-topleft: 4px; -webkit-border-top-left-radius: 4px; -moz-border-radius-bottomleft: 4px; -webkit-border-bottom-left-radius: 4px; }
.ui-corner-all { -moz-border-radius: 4px; -webkit-border-radius: 4px; }
.ui-corner-all-big { -moz-border-radius: 10px; -webkit-border-radius: 10px; }


but this class is not working with internet explorer...so what to do now ?