Im using Hostmonster and getting this error as well.
Im using Hostmonster and having the same problem.
Same issue. Have been uploading all day yesterday and then updated to 3.4.1. This am nothing will upload and I get the exact error
has failed to upload due to an error
File is empty. Please upload something more substantial. This error could also be caused by uploads being disabled in your php.ini or by post_max_size being defined as smaller than upload_max_filesize in php.ini.
