I did some quick googling how to use PHP to hook up with Exchange:
When an absolutely positioned element is adjacent in the source to a floated element, IE7 can sometimes “disappear” the absolutely positioned element. Debugging this with the Developer Toolbar is tricky, as nearly any hasPosition
-triggering change will cause the element to reappear — but the same change to the CSS won’t actually fix the problem.
To fix, check out this test battery (the fixes are in tests six and onwards).