Bug in IE 7 ... can not save proxy exception

recently I've upgraded IE6 to IE7 in my windows xp and vista clients at my office .. but now I'm not able to save proxy exception in advance tab, I want to set my browser to bypass the local intra net site from proxy .. every time I try to save it but it goes away after applying the settings ... in IE6 it was working ok

what it could be? is there any patch or update for IE7 to resolve this issue

Thnx