While the site works ok on IIS 7, there is one thing I need to finalize and find why I cannot download any file from it. Whenever I issue a transmit, I have something like this:

The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Runtime.InteropServices.COMException: The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[COMException (0x80070006): The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))]

[HttpException (0x80004005): An error occurred while communicating with the remote host. The error code is 0x80070006.]
System.Web.Hosting.IIS7WorkerRequest.RaiseCommunicationError(Int32 result, Boolean throwOnDisconnect) +2629371
System.Web.Hosting.IIS7WorkerRequest.FlushCore(Boolean keepConnected, Int32 numBodyFragments, IntPtr[] bodyFragments, Int32[] bodyFragmentLengths, Int32[] bodyFragmentTypes) +9625626
System.Web.Hosting.IIS7WorkerRequest.FlushCachedResponse(Boolean isFinal) +351
System.Web.HttpResponse.UpdateNativeResponse(Boolean sendHeaders) +431
System.Web.HttpRuntime.FinishRequestNotification(IIS7WorkerRequest wr, HttpContext context, RequestNotificationStatus& status) +116

The Event Viewer confirms a TransmitFile failed. I do not know if this is a security setting that this server need to have or if I missed something in the IIS 7 configuration.