My Forum Content Bunched into a corner!

[Kazeaki]

When I started my forum I chose a skin from hitskin that was in a phpBB3 version, and it displayed fine. I made a whole bunch of changes (mostly the colors and icons) To fit my forums topic and it was still looking perfect. One day it suddenly showed the content (all the category tables and such) Bunched up into the left side of the screen. I've tried switching to other versions but they all do the same thing, except for phpBB2. Why is this happening and how can I fix it? Please

[Sanket]

Install some other skin from hitskin.com
See if the problem persists. Also a link to your forum can be helpful.