problem with connection

I check my event log quiet often, i found this error every day between 5 and 8 times. What this means?
 CobeWeb/Formas/wf_as_AdministrarEndososFianzas.aspx Excepción: System.Web.HttpException: Error executing child request for ../Formas/wf_as_EndosarFianzas.aspx. ---> System.Web.HttpUnhandledException: Exception of type System.Web.HttpUnhandledException was thrown. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive.
My application has 3 levels, presentation, webservices, logic and data
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