Originally Posted by
WisTex
...despite the fact that your card has a MasterCard logo on the front, if you try to use it overseas at a merchant that ONLY accepted MasterCard but not Diners Club, your card will be declined..
Your card may have been declined, but there was some other reason. North American issued Diners Club cards are Mastercards, they comply with the Mastercard numbering standard, the first numeral is "5" and they are 16 digits. Cards processed on the Diners network begin with "36" and are only 14 digits.
BTW, the message you posted yesterday was not deleted. There appears to have been a database corruption. The message was listed on this page...
http://flyertalk.com/forum/forumdisplay.php?f=390
...but did not appear in the thread.