PHP4 - PHP5

I've been using an old verison of newsflash for some time. I absolutely love this theme. Made a few customizations to it. Anyway I've put off moving to PHP5 long enough and now I need to for simpleXML and ZendOptimizer to run. Switching to PHP5 results in a blank page. The theme but not be PHP5 ready. So I backed everything up and updated the theme. Now it runs in PHP5 but all the blocks are left justified. The left side bar, content area and right side bar are on top of each other instead of in columns. Also the User 1, User 2, User3 blocks cover the width of the body and are on top of each other instead of side by side. Then the nice-menus have disappeared. Is this because Suckerfish is overriding them? I imagine the solution is easy but replacing the entire CSS file will be a headache if thats what it takes.
Thanks.