I have installed this theme and now i can't access my forum all i see is the top part, my site hayabusa-1300.co.uk
Don't know if you've changed anything, but I've just got into both the site and the forum with no problems.
I'm using Firefox 18.0.2 with NoScript and AdBlock Plus, currently with nothing from your site being approved by me. I'll have a play and let you know if anything stops it from working
EDIT: Just allowed everything through NoScript, one at a time, then all together, and disabled AdBlock and the site still worked. Also tried it on Chrome and Opera, both fully updated, and didn't hit a problem there either.