You're welcome for the help :-)
Without looking at your page, IE is probably rendering the page as you want it, but it is the one that is wrong Are you using a valid doc type or is your page rendering in quirks mode? (ie without a doc type).
Earlier versions of DW didn't write in the full doc type - the latest versions do.
FFox is a standards compliant browers - much more so than IE. So if it looks off in FFox, I'd suggest you'd need to fix those errors and it is IE that needs the hacks not the other way round.
Yep, just had a look at the link you provided originally, and there is no doc type.
Look at
http://www.alistapart.com/articles/doctype/ which will explain what I'm talking about doc types.
As for your javascript (not java) errors, not sure that they would be caused by DW, but then again it depends on how you are using DW
A 3 column div layout is the hardest to accomplish cross browser, but if you check out the CSS forum here at Sitepoint there is a CSS sticky thread, look for Paul O'Briens' post (or look in his sig) for examples of various layouts.. I believe he has a 3 column one that may be of some help to you.
Nadia