Hi
I am having this problem too.
I am using ExpressionEngine v2.1.0 Build 20100810 on a fresh install on dreamhost.
I find if I navigate to the File Manager, the first file will upload OK.
The second file will upload and appear in the LHS list, but the “Uploading File⦔ graphic still displays.
If you try to upload a 3rd file at this point, you get the message “upload_no_file_selected” and the file list on the LHS doesn’t update, however if you refresh the page, the file has uploaded.