Hi,
I also have the above mentioned exceptions with the message "File does not exist." The exceptions seem only to occur if I debug the application from Visual Studio.
I'm using CuteEditor inside of a FormView which itself is inside a TabPanel. If I replace the CuteEditor tag in my page with a simple TextBox the exceptions don't occur anymore. So my assumption is that the exceptions are caused by the CuteEditor.
HttpContext.Current.Request.Url.ToString() returns in my case http://localhost/.../todo/null (the page with the CuteEditor has the url http://localhost/.../todo/Edit.aspx).
Cheers,
Thomas