Getting an elements coordinates (offset() issues)

Getting an elements coordinates (offset() issues)

What is the best way to get the position of an element relative to the document (accounting for margins as well)?

I would like to position another element over it. I'm using the offset() function but i am running into issues

1. The values for top & left returned in IE 8 (perhaps other versions) are incorrect. 
2. Offset() doesn't take into account margins of the element. And when margins are set to auto i cannot seem to get the correct margin values to use

Thanks for the help.