Using SIG 2.2 on Joomla 2.5 I get the following error:

JFolder: :files: Path is not a folder. Path: /home/content/90/9420090/html/images/1969/photos/Back_in_The_Day/

My images folder actually starts at the root not with html.

I also use AllVideos but do not have any issues with that plugin.

So, can you correct your path?

I found the problem. I had the wrong location in the plugin. I didn't notice that when I made admin changes.

;)