Over the past few months, I've been on four mixed UA/CO trips. Whenever the first segment is on CO, I always get this message when trying to check in online:
We are unable to complete the check-in process as a valid eTicket coupon cannot be found. Please contact a Continental Representative at 1-800-300-1547 for assistance.
I call CO and they can't explain why this is so. Today, the agent said that because I'm upgraded from SFO-LAS (a UA flight), this is why I cannot check in the HNL-SFO flight (a CO flight).
Huh?