Well...

 

For multiple upload, I know there are two possible modes: Flash and Silverlight. We decided forcing using the "Flash" mode in our product by explicitly set the property UploadType to CuteWebUI.UploadType.Flash. In that way, we know what customer are using when they complain about the multiple upload (otherwise when they report errors, it makes it even more complicated understanding what's wrong).

 

And in any case, we get also the "unable submit form, frame not ready" when using the IFrame mode (where flash isn't used). Do you have an answer for that one?