SharePoint PeoplePicker getting hidden in IE7(without SharePoint Ribbon) with jQuery UI datepicker

When jQuery UI DatePicker is clicked, the people div area gets hidden. It works fine in IE8.

The div with id ends with  _upLevelDiv gets hidden automatically. Values are not lost. Not able to fix the problem by putting style elements.

Its not border issue. The whole data containing div gets hidden. Try without SharePoint Ribbon in IE7. Clicking the browse button in people picker also disables the div.

Thanks,
Prasanna.

Thanks, B.J.Prasanna.