While recently working with CFMemu in CF8 I ran across an issue with IE. The sub menu items were appearing on top of the parent items. After tons of digging I was able to figure out the problem. The problem was when setting the CHILDSTYLE in the cfmenu tag and putting in "overflow:hidden". For some reason this caused the sub menus to display over the parent, but only in IE. Below is a sample of code that will demonstrate. This is taken from the help docs. I took out some menu options to shrink the code.

view plain print about
1<cfmenu name="menu" type="horizontal" fontsize="14" bgcolor="##CCFFFF" CHILDSTYLE="overflow:hidden;">
2 <cfmenuitem name="coldfusion"
3 href="http://www.adobe.com/products/coldfusion" display="ColdFusion">

4 <cfmenuitem name="buy"
5 href="http://www.adobe.com/products/coldfusion/buy/" display="Buy"/>

6 <cfmenuitem name="documentation"
7 href="http://www.adobe.com/support/documentation/en/coldfusion/"
8 display="Documentation"/>

9 </cfmenuitem>

Hope this helps you avoid the headaches I received.