We are having the same issue: Win2003, Integrated Windows Authentication, Allow Anonymous turned off.  It prompts for credentials and the upload fails.

Any progress on this?  If I take your sample and upload it to our server, disable anonymous access, and use integrated windows authentication, I get the same result.  It only works when Allow Anonymous is checked.  FYI, the identity used with Allow Anonymous is (currently) an Administrator, also the identity used by the App Pool is ...

OK, I tried adding UploadType=''IFrame'' to the HTML.  Same result: it works locally, but not remotely.  Here is my HTML control declaration:   <CuteWebUI:UploadPersistedFile UploadType=''IFrame'' runat=''server'' ID=''uplFile'' InsertText=''Browse'' ManualStartUpload=''false'' MultipleFilesUpload=''false'' ...

Bear in mind that from the same browser, it works if the web server is local, but does not if the web server is remote.  How could Flash be playing a role in this case?

Any ideas on this?

It is IIS6, it is running in an app pool that uses the Network Service identity.  I granted Modify permissions to the UploaderTemp folder for Network Service.

It is using windows auth, and allow anonymous is unchecked.

The UploadPersistedFile control works locally, both via the built-in Dev Server in asp.net, as well as locally on the server itself.  But it doesn't work from my browser to the remote server.  It starts to upload the file, then prompts for credentials when it gets to the end.  If I re-enter my credentials, it prompts again.  If ...

OK, thanks, I'll give that a try.  Was that somewhere in the documentation?  I looked...

I would like it to work like this:   User clicks browse, selects a file, and the upload starts -> I get a client side event, the event handler for which can disable appropriate screen controls while the upload proceeds.  Looking for a javascript BeginUpload event or something like that.   User clicks cancel during an upload ...