Image store not working with Mac os Lion

I have set up a clients site on wordpress I am running Snow leopard, and all works fine. I went to see my client who is running Lion 10.7.3 on a brand new iMac, but when my client goes to import photos into a gallery on image store within wordpress the import/browse photos seems to upload and it looks like its doing something, but then nothing happens no images are uploaded, do you know of anyone who has had similar problems? or know a solution? All is fine on my system when I go into WordPress, but on my clients computer there is no “select files” button, just a box and browse.

It is quite fundamental to the website that my client can upload photos and create galleries as she is a photographer and was counting on creating the galleries herself. The only other computer she has is an ipad, I have one as well and WordPress does odd things on the ipad too so thats no good.
I installed Lion on my imac – myself to see if that was a the problem and sure enough the same thing happened to me wordpress was behaving oddly, but even worse , the buttons for upload images as in the attachment were all over the place!!

Any help would be gratefully received.