webrob,

IE6 & 7 do not properly support the CSS :hover attribute. At my end, it looks perfect in FF2, IE6 has no drop-downs at all, and IE7 has them but they're shifted to the right.

There is a lot on the web about IE's CSS rendering bugs. At present, I don't know of any pure CSS drop-down menus that work in IE6. You have to use JavaScript to get around IE6's limitations.

I always start with Son of Suckerfish as my code base and build on that. Best thing is to create two IE conditional comments (one for IE6 and one for IE7) so you don't modify the code that you have working with FF.

http://www.htmldog.com/articles/suckerfish/dropdowns/

BrandTim