Do you have a blank space where the column should be? Or does the center go all the way to the right edge?

There are two column width settings - column width and column boxes width, provided so you can have custom margin/container effects. They both need to be set to function properly.

It is possible to set a flag in /includes/templates/your_template/common/tpl_main_page.php to disable the right column (or other elements). Search that file for $flag_disable_right.