Server Timeout Error

[djn]

I'm having problems executing a calculation procedure through an ASP.NET site to SQL Server. Not much detail, I know, but hoping someone on here can help. The procedure works in some instances and in some it does not. Here is the error message when the calculation bombs....Server Error in '/' Application.Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. 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.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.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: [SqlException (0x80131904): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.] System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1948826 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4844747 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2392 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +204 System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +954 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +162 System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +175 System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +137 Database.ExportFas143CostData(Int32 PermitNameID, Int32 FiscalYear, Int32 FiscalMonth, Int32 CashFlowYear, Decimal WeightedCost) in d:\CC.NET\AROTest_web\ARO_Web\App_Code\Database.cs:1777 AroCalculations.CalculateReclamation(String ReclamationDataID, String PermitNameID) in d:\CC.NET\AROTest_web\ARO_Web\AroCalculations.aspx.cs:390 AroCalculations.CalculateSelected_Click(Object sender, EventArgs e) in d:\CC.NET\AROTest_web\ARO_Web\AroCalculations.aspx.cs:359 System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e) +111 System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +79 System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +175 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565Version Information: Microsoft .NET Framework Version:2.0.50727.3053; ASP.NET Version:2.0.50727.3053