There seem to be a few bugs in your html/php forum when viewing it in Safari (Mac internet explorer). Just though id let you know the whole top of the page is white and the forum is screwey.
Unfortunately I don't have access to a Mac but could you provide a screenshot of this so I can do some guesswork?
EDIT: Oh boy, that was a major problem. Apologies to everyone over the past two weeks, I only just noticed that there was something actually wrong as it worked fine on my computer which is no doubt the only place it worked.
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If for any reason you're not completely satisfied, I hate you.