imageUploader.TempDirectory = _uploadFolder;
Please do not use the TempDirectory property any mode.
While the uploader have been upgrated to v2.0 , this property is not compatible with the Flash upload mode.
We haven't prepaired the document on this issue , sorry.
If you want to change the default , you can set it at web.config appSettings :
<add key="CuteWebUI.AjaxUploader.TempDirectory" value="~/TempDirectory" />
you can specify a physical path too, for example "d:\temp" or "\\server2\shared folder"
Regards , Terry.