BTW, who issued the ticket ? i.e. whose document it is on ?

In my last RTW, UA Reservations refused to make any changes, and I had to call Austrian which had issued the ticket. Austrian was happy to make the changes and it showed up on checkmytrip.com.

But, later on the same journey, SAS was happy to make changes to the SAS segments. Even re-routing..

so, i guess the problem is entirely with the different Reservation ssystems used. I would get hold of the new booking reference from UA.

If you are using a BKK travel agent, then I suspect it's a Thai ticket, in which case you'll always get good response from Thai.

thanks