OLCI is where all the problems are. As long as your ticket is in order and your have your credit card (in case it needs to be verified), it should be OK.

My daughter changed her flight about a day before her original return flight to US. A few days later, the e-ticket still showed the old date and there was still no charge to AMEX. It got me a little worried, but she still checked in at the airport with no problem.