Excepción no controlada

Hola modifique la parte q me mencionaste pero aun sigue
el error ese cuando llega al registro 115 sale el mismo error
Public Overridable Function BuscarCONTRATO() As Data.DataSet

Dim adaTemp As SqlDataAdapter

Dim dtsTemp As Data.DataSet

Dim prnCodigo As SqlParameter

Dim con As SqlConnection

Dim trnTemp As SqlTransaction

Dim cmdTemp As SqlCommand

Dim prnNroContrato As SqlParameter

prnNroContrato = New SqlParameter("@NroContrato", SqlDbType.VarChar, 30)

prnNroContrato.Value = strNroContrato

trnTemp = ComenzarTransaccion

con = trnTemp.Connection

cmdTemp = New SqlCommand("CONTRATO_Buscar_Nombre", trnTemp.Connection)

cmdTemp.CommandType = CommandType.StoredProcedure

cmdTemp.Parameters.Add(prnNroContrato)

cmdTemp.Transaction = trnTemp

Try

adaTemp = New SqlDataAdapter(cmdTemp)

dtsTemp = New Data.DataSet

adaTemp.Fill(dtsTemp, "CONTRATO")

trnTemp.Commit()

Return dtsTemp

Catch ex As Exception

trnTemp.Rollback()

MsgBox("NO SE ENCONTRO NINGUN REGISTRO INTENTE NUEVAMENTE" + vbNewLine +
"DETALLE:" + vbNewLine + ex.Message.ToUpper, MsgBoxStyle.Critical,
"MENSAJE")

Finally

If Not con Is Nothing AndAlso con.State = ConnectionState.Open Then

con.Close()

End If

End Try

End Function

esta bien mi cadena de conexion

Protected Function Conectar() As SqlConnection

Dim strCon As String

Dim conTemp As System.Data.SqlClient.SqlConnection

strCon = "server=" + Servidor + ";" _

+ "database=" + DB + ";uid=" + Nombre() _

+ ";pwd=" + password() + ";"

conTemp = New SqlConnection(strCon)

conTemp.Open()

Return conTemp

End Function

Protected Function ComenzarTransaccion() As SqlTransaction

Dim conTemp As SqlConnection

conTemp = Conectar()

Return conTemp.BeginTransaction()

End Function

realmente lo estoy cerrando o q puede ser gracias