[Plugin: Image Store] Image store image upload facility not working running mac osx 10.7.2

I went to see a client to show them how to use image store, but when we went to upload the images within the gallery section when you go to create a new gallery, the upload images panel would not work, it said it was uploading the image but then nothing would appear, then the pg just jumps back to the top and when you scroll down to see the image upload nothing is there. Is this an compatibility issue with Mac osx 10.7.2 ? as it works all ok on my system.

http://wordpress.org/extend/plugins/image-store/