Hello - having an issue with drag-n-drop where sporadically a file being uploaded will hang at 1 second remaining... right before the file is, I assume, sent to the server.  I can set the upload page to a non-existent location and it still occurs, so the issue lies somewhere prior to the file being processed by the server.

The file and file type doesn't seem to matter, I've tried a variety.  In one attempt the PDF file will upload fine, then a subsequent upload it will hang and never send, rocketing the IE browser CPU utilization to 55%+.  And once it "hangs" on one request, hitting the Cancel button and attempting another is a guaranteed hang.

Multiple browsers have been tried, same issue.

All of my tests have been with small files, less than 50 KBs. 

Any ideas, suggestions? I'm just not sure where the issue could lie... maybe a server configuration issue causing a loop in the code?  We're using IIS 7 and ASP.NET 4 (webforms).

Thanks for any help you can provide!