i dig the menu very much, and the logo even more. very shweet design. the colors are great, too. vibrant, but not too bold. great look.
font-wise, id stick with verdanna over arial -- its just easier on the eyes (a web-designed font, after all).
you should get nix the doubled menu (my profile, register) -- unnecessary with your flash header (check "compact headers" add-on)
other than that... i dunno... the 100% table width? i prefer it with a lil "edge" (like maybe 90-95%) but thats justa preference choice.
overall, great work.
) is I would place your calendar in public_forum_summary.pl near the "Recent Visitors" rather than the bottom since calendar events are important. Other than that very nicely done. 
