OWA not display notification when new message is arrive



I use OWA to access email. We used Exchange 2010.
I not get display notification when new message is arrive. The option is
selected in OWA to show it but it doesn't work. But sound notification is
working when message is arrive. In Exchange managment Reminders and
Notification is set to Enable, I turn off pop up blocker, the OWA site is set
as trusted site, set cookies allow from OWA but nothing is worked. I tested
that in IE 6, 7 ,8
Please help!!!
.