Invalid Token Error when sending PM's

When I send a PM through my site: thechickenloop.com, it responds with a blank page that says in the top corner "Invalid Token"

any ideas as to why this occurs or what I can do about this?

Thanks in advance if you can help me out with this situation!

1st: Please use forum search:

www.joomlapolis.com/component/option,com_joomlaboard/Itemid,/func,view/catid,25/id,58350/#58350

The error could also appear when your menu link is not correct:

- Have you created a menu link to uddeIM component?
- Check if the link still points to the correct component.
- Do you use two or more menu links? Are these links restricted?
- Is there a "deleted link" to uddeIM is the trash? If so empty the trash can.
- Do you use Joomla SEF? Do you use the correct .htaccess file?
- Do you use a 3rd party SEF? Does it work without SEF?