JQuery UI popup elements not positioning correctly

I am using both JQuery UI 开发者_开发技巧Dialog and JQuery UI autocomplete both have the same erroneous behavior when they popup, the position is always 0,0! I have tried some different position arguments when popping up the dialog but non seems to help.

Any clues? Is this a bug in the position calculation in JQuery? Or is this some css bug?

Versions are 1.4.2 and 1.8.0

Ok I found out that this error was caused by a external jquery script plugin called jquery.dimensions... - "As of jQuery 1.2.6, the dimensions plugin has been merged into core." So I just removed the plugin and now everything is working as expected.

If Okku's answer doesn't fix things, you may find you've forgotten the file jquery.position.js from your includes.