In all the following test cases the box with black border is a left float containing some text and links. The green box follows the float and contains italic text (except where differently noted.)
Case 1: in IE7 the float is incorrectly overlapped by the green background. None of the links in the float work (including the non overlapped ones.)
Case 2: The float and the green box are enclosed in a hasLayout container (with blue border.) The overlapping problem still occurs. The not overlapped links now work.
Case 3: Like case 1 but without italics: no problems.
Case 4: Like case 1, but with position:relative on the float. The problem is fixed.
Case 5: Like case 2, but with position:relative on the float. The problem is fixed.