Error Uploading Image in CiviMail Module on Wordpress Installation

When attempting to create an email template in CiviMail, if you click on the 'Image' button, then choose the Upload tab, browse and select a file, then click the 'Send it to the Server' button, you are rewarded with the following message:

Sorry but we are not able to provide this at the moment.
You must be logged in with proper permissions to edit, add, or delete uploaded images.

I've seen this reported by Drupal users and most of those reports included recommendations to upgrade to a later version of CiviCRM which I have done. Basically, I've made all of the changes I know to make and still the error occurs.

The only workaround that I've confirmed works, is to use the 'Media Library' in Wordpress, pre-upload all of the required graphics and save the URLS, then when editing the template, just copy and paste URL on the first tab when you click the 'Image' button. This will insert the image and it will work, but it is a pain to have to pre-load every image before working with it.

Any ideas, suggestions or otherwise helpful comments out there?

Thanks in advance!