When uploading very small files in ASP.NET using the progress indicator and the HttpModule, the IsEmpty property returns "false". If you do not check IsEmpty, the file will be successfully uploaded. However, if you have coded your application so that an error message is returned and the file is not saved when IsEmpty returns false, your user would experience something like the following:

• The user selects a file and submits the web form
  
• The progress indicator pops up and shows a file being successfully uploaded, including the correct number of bytes
  
• The response page returns an error like "no file was selected"
  
• The file is not saved on the server
  

This problem generally only occurs in IIS6

This problem relates to a minor change in the ASP.NET implementation between IIS5 and IIS6. This change caused a timing conflict with small uploads where FileUp's progress indicator deletes temp files before the upload page can save them.

This issue has been fixed. Please upgrade to the lastest version.