We are experiencing a similar issue..
it appears to be related to the new ranking that's been implemented..
I'm able to upload fine as admin ...
but if I log into a test account with only member access.. I don't get the pop-up window for the upload process..
looks to be a javascript error
one member posted what he was seing
which if is not a typo on his part.. it appears a slash is being placed where a period should be in the URL..
hope it helps