From the catch on the error:
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream)
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.SqlClient.SqlCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.FillFromCommand(Object data, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable)
at OakLeaf.MM.Main.Data.mmDataAccessSql.FillDataSet(DataSet ds, IDbDataAdapter dbAdapter, String tableName, Boolean clearOnFill)
at OakLeaf.MM.Main.Data.mmDataAccessSql.FillDataSet(DataSet ds, IDbCommand command, String tableName, Boolean clearOnFill)
at OakLeaf.MM.Main.Data.mmDataAccessSql.FillDataSet(DataSet ds, String command, String tableName, CommandType cmdType, IDbDataParameter[] dataParms, Boolean clearOnFill)
at OakLeaf.MM.Main.Business.mmBusinessObject.FillDataSet(DataSet ds, String command, String tableName, String databaseKey, CommandType cmdType, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName, String databaseKey, CommandType cmdType, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName, String databaseKey, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Globalization.mmMessageManager.GetAllMessages(Object languagePK)
at OakLeaf.MM.Main.Globalization.mmMessageManager.GetMessageCache(Object LanguagePk, Boolean ForceReload)
at OakLeaf.MM.Main.Globalization.mmMessageManager.GetMessageCache(Object LanguagePk)
at OakLeaf.MM.Main.Globalization.mmMessageManager.GetMessage(String messageKey, Object languagePK, Boolean returnMessageKeyIfNotFound)
at OakLeaf.MM.Main.Globalization.mmMessageManager.GetMessage(String messageKey)
at OakLeaf.MM.Main.Business.mmBusinessObject.BuildConcurrencyExceptionMsg(DBConcurrencyException e)
at OakLeaf.MM.Main.Business.mmBusinessObject.HandleException(Exception e)
at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(DataSet ds, String tableName, String databaseKey, IDbDataAdapter dbAdapter)
at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(DataSet ds, String tableName, String databaseKey)
at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(DataSet ds, String tableName)
at OakLeaf.MM.Main.Business.mmBusinessObject.SaveDataSet(String tableName, Int32 currentRow)
at SRA.CashSales.mmButton5_Click_2(Object sender, EventArgs e) in c:\win_projects\fleetpro\cashsales.cs:line 851

is it an int isn't an int?