My page at http://www.VirtualVermont.com/calendar/index.html works exactly as it should: mouse over the different regions on the map, the rollover action highlights the region,the name of the region appears above the map via slave image, and a click brings you to the calendar page for that region. This page is made in FWPro 3.5.15.
Same page, converted to FWPro 5.3. It works properly when previewed in browser, but the uploaded version does nothing. No rollovers, no slave image, no links to the calendar pages.
I had an issue when I moved to FW5 also. I had to go back and check all of my rollovers and target images, and make sure none had migrated to FW5 as layers. FW5 worked fine after a few tweaks of the page.