Unknown order in transaction form

This issue was split off from #1309652: Trying to get property of non-object in idealui_merchant_list(), where it was introduced in comment #11.

Notice: Trying to get property of non-object in idealubercart_transaction_form_access() (regel 142 van
/home/~~~/public_html/sites/all/modules/idealubercart/idealubercart.module).