Manage fields (new contenttype)

Hi..

Is this the right place for this message?

I was trying to follow this guide (http://thedrupalblog.com/adding-jquery-image-carousel-your-node-view) to add an image carrousel.

When I added a new contenttype and pressed 'Manage fields', I see these messages:

recoverable fatal error: Object of class stdClass could not be converted to string in /usr/share/drupal6/modules/image/contrib/image_attach/image_attach.module on line 177.
recoverable fatal error: Object of class stdClass could not be converted to string in /usr/share/drupal6/modules/scheduler/scheduler.module on line 100.
recoverable fatal error: Object of class stdClass could not be converted to string in /usr/share/drupal6/modules/forum_access/forum_access.module on line 140.
recoverable fatal error: Object of class stdClass could not be converted to string in /usr/share/drupal6/modules/image_gallery_access/image_gallery_access.module on line 117.

I use the default Theme, and as far as I know, no development modules.

Anyone know where too look for the cause?

Greetings,

René.