Unnecessary popups open while ruuning test suite

I'm running selenium tests to test application through Junit. I login
to
application,check UI text and log off. when i log off, current
browser gets closed and one more browser opens with popup the webpage
you are viewing is trying to close window.Do you want to continue. And
this happens for the starting tests.After some tests,when log off button
is clicked,it redirects to login page in same browser window. In
initial tests only it behaves differently.



Manually when i log off application,it redirects me to login page on same browser window.
But from selenium tests,it closes current browser and opens another browser with popup.


How can i avoid generating these popups?
I'm using selenium jar 2.30(RC)
IE 8 ,Windows XP

Try adding the URL in trusted sites in oyur browser configuration, and reduce the browser security level to low.