Im afraid not mate, dont even get to select a file to upload, just doesnt bring up the explorer.
Something else i have noticed is that when i select a folder it doesnt bring up the listing of files that are in that folder already like on your screenshots on your site.
I can upload ( allthough i think it is not very logic to have the UPLOAD button first and then the choose uploadfolder, i would swap them but thats just me ).
The problem is with the tab choose existing, it just doesnt show any files.
i am using IE 8 btw
Oh, i tryed it on my own site and there i can upload new files also. Its the existing tab that gives the problem.
EDIT 2 >
Sorry UncleCheese, i was jumping conclusions...It just looks like upload is working, but when its finished with the upload the attached files remains empty an the file does not attach to my page in the CMS.
The file IS actually uploaded to the folder i choose but it doesnt show in the CMS.