The Admin page is sometimes blank, no options appear. Some other times, the page displays ok, but changes are not saved.

Besides, I get a big blank screen with the following error message when I click on the "Imagefield Gallery Content Types" link:

Fatal error: Cannot unset string offsets in [full path]/includes/form.inc on line 319

I am running Drupal 5.10 under PHP 5.2.0-8