[jQuery] BlockUI 2.X ver. not ful screen overlay in WSS 3.0 new item list form

Hello everybody,

first of all I want to say BlockUi plugin is very useful, perfect...
but now I've tried it in my WSS (Sharepoint) web form. I want to block
whole page, but it blocks just part of screen. When I click on
horizontal or vertical scroll then the screen below is not overlayed
and look like not blocked...

Please help me to solve this issue...

Thank you Vasek - Slovakia