Weired Behaviour in JSP Pages

Hi,

I am facing a problem in scroll bar and also button.

My start page has some details listed in a table with checkboxes. When I select more than one check box and edit(multiple edit) a pop up comes, but i wish to cancel it. After this pop up is cancelled, the previous page is dispalyed without the scroll bar. When i minimize the window and maximize it again, I get that scroll bar.

Could anyone tell me why is this behavior?

Thanks,
Rijil