Upload periodically not working

[Justin Crossley]

I am finding that sometimes on postback none of the selected files are uploading and there is nothing in the InvalidFiles collection. It just refreshes the form clearing the file path boxes. There is no obvious difference between what I do when it works and when it doesn't. I even use the same files.

It is not a file size problem and I am not using an updatepanel.

Does anyone have any ideas?

Thanks

[Vesko]

Do you have any ASP.NET validators on the page? They might be failing.