Alert messages are reading twice in IE 8 with JAWS version 13

Hi ,

I have implemented the application, which consists error alert messages on tab out. The error message will display in pop-up window..

The pop-up window code is like

<div role="alert" > Please enter first name </div> 

When I read the message with JAWS-13 in IE7,IE 8,IE 9 it's reading twice, where as in Firefox its reading only once.

Please let me know, is it problem with IE or JAWS version?.

Regards,

Rambabu