This usually happens when a piece of content (usually in a table) is wider than expected, causing the main part of the page to be too wide to fit in its space. We're looking into moving to a flexible-width layout to correct this and better accommodate a variety of layouts, but in the meantime, see if you can spot and correct the piece of content that is too wide.
Open Journal Systems Team
Don't miss the First International PKP Scholarly Publishing Conference
July 11 - 13, 2007, Vancouver, BC, Canada