Ah, one of my favorite hacks! (IE7
does support min-height, BTW.)
Is there a reason your min-height is 500px and the other height declaration is 530px? In my experience with this hack, I always use the same values and have not had any issues.
Well, I guess one thing to look out for with this hack is
nesting. If you use this min-height hack an an outer div, and then also apply the same hack on an inner div, the inner div will not follow the rule as you may suspect.
Is this the only instance of the min-height hack in your layout?
UPDATE: Just saw the link and reviewed the style sheet. It does not appear this is an issue with nested hacks.
Consider the following:
min-height: 500px; // IE7 will follow this rule, IE6 will not
height: auto !important; // IE6 allows height > 530px thanks to IE6 !important bug, even though called before height: 530px rule
height: 530px; // IE6 will begin with at least this height, never less (hence min-height hack)
http://www.dustindiaz.com/min-height-fast-hack/