Plugin: Meteor Slideshow

Hello,
I apologise if this question has already been asked before as I’ve searched but couldn’t find an answer. I’ve downloaded Meteor Slideshow and set it up as per Josh’s video.

My trouble starts when I go to set a featured image. I’ve tried to set the featured image from my computer and from the media library but no matter which image I use, when I click on “Use as featured image” it says it’s saving it, and the word “Done” pops up under the sizes for a while then disappears. The only other option there is Delete. If I then click on “Save all changes” I’m directed back to the list of all images in my media library.

In Josh’s video the upload area appears as a small window, however in my WordPress it takes up the whole screen, and I’m wondering if perhaps Meteor Slider isn’t compatible with WordPress 3.4.2?

I haven’t included a link to the site I’m referring to because you can’t see anything about the slider as I haven’t gotten that far. I’m relatively new to WordPress and am on a steep learning curve but just can’t work this one out. Thanks for your help in advance.
Shan