Keywords: FCKeditor, drupal, firefox, gwProxy, <!--Session data>
When using FCKeditor and Firefox with Drupal strange blocks apear at the end of a post. After searching and testing this turned out to be caused by one of the installed Add-ons of Firefox. In our case it was caused by "The Browser Highlighter".
This problem is nog visible in Internet Explorer and Chrome.
To correct the problem, disable all Add-on's and test if the problem is gone. If required enable the Add-on's one by one to find the module that is causing the problem.
