But some thoughts for you to consider: You're not confusing ID selectors (e.g. #Menu and ID='Menu') with class selectors (e.g. .Menu and class='Menu') are you? Also, #Menu>A:link is more restrictive than #Menu A:link as the latter means you can put something else between the #Menu'ed tag and the A tag.
No, I'm not confusing ID selectors with class selectors.
I first tried it with only ID selectors like <div id="Menu"> in my HTML, and #Menu>a:link in my CSS. In that particular instance, my pretty menu box that showed up with white links on an orange background in Mozilla was a completely orange box in IE.
What I did to fix it was add class="menu" attributes to all of the <a> tags in the HTML, and duplicate the "a" definitions in the CSS to be a.menu as well as #Menu>a.
I can't say as I truly understand why that works, but it does.
IE is borked.