IE ignores "margin-top" sometimes

With a relatively placed container DIV that has an absolutly place DIV inside it, IE ignores the top-margin of the top DIV that is inside the container. This DIV can have no positioning applied or it can be relatively positioned, but IE still ignores it. Other DIVs below it can have top margins and the top DIV can have a bottom margin, but for some reason the top margin of the top DIV is ignored. I found that to be the case with IE6 and 7.