Datepicker calendar displayed on top of the screen for a scrolling window

Datepicker calendar is displayed on top of the screen rather than the being displayed next to the text box. The issue seems to be on a scrolling window, on a non scrolling window it is working fine. I have attached  a screen shot below. Any ideas how to solve this please. I am using  the default "jquery-ui.css"

• Topic Participants

• sajhahelp

• jakecigar