I get this message: "System.Web.Services.Protocols.SoapException: Server was unable to read request. ---> System.InvalidOperationException: There is an error in XML document (1, 345). ---> System.StackOverflowException: Exception of type System.StackOverflowException was thrown.


 Source: "System.Web.Services"
    StackTrace: " at System.Web.Services.Protocols.SoapHttpClientProtoc ol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtoc ol.Invoke(String methodName, Object[] parameters)
   at ProjectCMA.CMAWebService.CMAServices.SaveFichaByRe f(cmaFicha xmlFicha, String username, Boolean isNew) in C:\My Projects\cma_net\CMA Project\Web References\CMAWebService\Reference.vb:line 260
   at ProjectCMA.frmFicha.btnGravar_Click(Object sender, EventArgs e) in C:\My Projects\cma_net\CMA Project\Ficha.vb:line 695"


Any clues why? thank you in advance.