At this moment I don't see a lot of problems in Internet Explorer 6 on your main page except that the top banner doesn't stretch across the top. The font sizes seem to be different in Internet Explorer and IE.

This page is wider than the main page and the top banner looks strange:
Seashell Home Decor Accents

Even with hand coding, browsers tend to to what they like. Firefox obeys only text sizing codes it likes, with very odd results, especially when people change the text size preferences. IE6 does not understand some div commands, which can be disastrous.

All code from WYSIWYG tools has to be cleaned up to some extent. Sometimes junk code inserts something that strops search engine spiders so they cannot read your page. Beware.

In general, it is better to do simple things that will probably work everywhere. Your code is very complex for what it does, because that's what the application did.

If you have a serious business, consider hiring a professional to make your site. Then you can yell at them when it doesn't look right.