I flew to Miami last week, changing planes in Cleveland and taking a Northwest flight on one of four legs. All the miles and legs were credited to my account, except the Northwest leg. I don't often fly other airlines so I wonder if it takes more time for those miles to be credited?

The boarding passes were all Continental, but it was a Northwest flight that brought me home. I'm right on the verge on hitting Gold again after a year in Purgatory as a Silver (don't know why they even have Silver- it was a terrible year for upgrades!) and I don't want to miss any miles or segments. I want to be sure I get it done before the end of the month, so any ideas? Is this normal for a partner airline?