[jQuery] Position()

Hello guys,

i started another thread about the FullCalendar plugin, and I've
noticed what's happening.
The css 'top' and 'left' properties from the css aren't being
calculated properly...
The functions to calculate that uses the 'position()' function of
jquery, but it is always returning 0, 1 or -1, no matter where the
element is on the page...

Does anyone know if this is some jquery bug or something?