on the checkout page, change:
$nextIndex = count($WA_PP_ECO_Set_params[0]);
$WA_PP_ECO_Set_params[0][$nextIndex] = "PaymentAction";
$WA_PP_ECO_Set_params[1][$nextIndex] = "Authorization";
to:
$nextIndex = count($WA_PP_ECO_Set_params[0]);
$WA_PP_ECO_Set_params[0][$nextIndex] = "PaymentAction";
$WA_PP_ECO_Set_params[1][$nextIndex] = "Authorization";
$nextIndex = count($WA_PP_ECO_Set_params[0]);
$WA_PP_ECO_Set_params[0][$nextIndex] = "OrderDescription";
$WA_PP_ECO_Set_params[1][$nextIndex] = "www.lovethisone.com Order";
the login question, you asked in another thread.