checkmytrip.com is an Amadeus site. IMO Expedia uses Galileo. If a PNR is ticketed via other system checkmytrip.com will not post the e-ticket numer (I think BA and possibly QF are the only exceptions). The reason is that checkmytrip.com is only posting data available under the FA field (i.e. field that holds e-tkt information). If a ticket is issued by Galileo or Sabre or Worldspan, FA field is not created in Amadeus and SSR TKTE (meaning: 'Special service Request e-ticket Information') is created, instead. So, as there is no FA field, thus no e-ticket information in checkmytrip.com