What browser are you using? As a check try with a different browser if you have a 2nd browser on your system. Chrome for example has had some problems interfacing with the online web tools.
You can also upload your files by an ftp client and then they are marked public by default. So you don't have to mark each one public. Also there is no 8mb upload limit on ftp uploads and you can batch upload numerous files at once. CoreftpLE is a good free one. Windows has one built in. Open any windows explorer window such as 'my documents' and erase the address bar. Type in "ftp://upload.comcast.net" and follow the prompts.