Can't view Media Content as Thumbnails

I just installed the Media 7.x-1.0 and related media modules (like Media Browser Plus 7.x-1.0-beta3) on an existing site.

When I go to /admin/content/media/thumbnails I get nothing.
When I go to /admin/content/media/list I get a list of all the media that exist in /sites/domain.com/files directory.

I tried importing media with /admin/content/media/import and all this did was create a bunch of duplicates for me the files directory and in the /admin/content/media/list.

I tried clearing my cache both before and after importing, and this did not help either time. I'm working on a development copy of the original site hosted on a Barracuda Octopus Aegir Hosting environment, so all cacheing is turned off.

When I go to a WYSIWYG field (using WYSIWYG module with CKeditor) and use the Media Browser and go to library, I can see and browse all the thumbnails there.

I'm not sure if I doing something wrong or if this is a bug with the module, so I'm marking this issue as support request because 9 out 10 times it's me doing something wrong.

Thanks for your help in advance!
Steve