Hi,
I just checked all logs..
The form data is OK, the upload module can read it.
after Response.Write("OK") , there is a GENERAL_NOT_SEND_CUSTOM_ERROR
Maybe the error is that , the uploader module do not set Response.StatusCode=200 before Response.Write("OK")
I will create an application and test it in my PC and then give you a response.
Regards,
Terry