[Lynne]

Try disabling your plugins and then see if you still have this problem.
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

PHP Code:

define('DISABLE_HOOKS', true); 


If you don't get the problem after turning them all off, then turn them on one-by-one until you do get the problem. This should help you figure out which plugin is causing the problem.

Also, you may want to look in your error_logs and see if there is anything in there (probably not, but you never know).