I tried to change two tickets online within the last days . . . but the booking system seems to be screwed up in regard to the fare classes being offered as new options. The system only shows me a small part of the fare classes that would be available if I would do a new ticket purchase . . . and it never offers me the cheapest fare classes. Also, the system shows me only a few flights and not all departure times that are definitely still available (according to a test booking of a new ticket).

So I think I might have to call whenever I like to change a ticket. This looks like a major online system glitch.

Anyone else encountering these problems?

Several months ago I ran into a major hassle after an online change (the new ticket was never reissued, and thank goodness I discovered it the night before and not at the airport).

The agent recommended always changing flights with an agent, and I heed that advice.

In your case, figure out what's available by doing those new searches, and call in armed with that information.

Today I had my August flight to Brasil re routed (automatically by CO) to the new IAH - GIG route. My return flight was originally GIG GRU EWR BOS... When they made the change it became GIG - IAH and then GRU EWR BOS Well, I called the elite line and spoke with a very nice and helpful person. We straightened it out fairly quickly and things are fine now. I originally bought the L fare as the price was as low as I ever remember paying to fly to Brasil. My return trip is now B class... Obrigado Continental!

this has happened to me at least twice, I end up calling and specify what flights I am after and luckily they have both been available (as they should because they show if you simply try to buy a new ticket)

also in the last two ticket changes the usual 'stuck in between reissuing' problem has surfaced.

in both occasions the same thing happens, I go online do my thing, get the change done, then I don't get the confirmation email and when you click on 'receipt' it shows the old stuff, I then call the helpdesk who swears everything is 'fine' and they are going to resend me the ticket, they do so, then I get TWO copies and magically the receipt shows the right itinerary with the change fee $ applied etc.

In other words, be extremely careful

I also had the exact same situation happen recently, where I was only offered a few choices that were not even close to those that I would have been offered had I purchased a new ticket...and as you mention, especially the cheapest fare classes. However, after trying a couple of times, I simply entered an "L" class under "Enter specific class of service" when I was re-booking and voila, I had all kinds of great, cheaper choices. Some were actually too good to be true to the point where I had to go to the internet help desk and first, spend ten minutes convincing them that I actually know what I'm doing, and then convincing them that the fare actually existed. I ended up getting SEA-MEX for $207 + $104 for taxes, so for that change I didn't mind paying the change fee

I just wish we could call in and just pay the $150 change fee and have them issue the balance of the ticket in the form of a travel voucher that can be redeemed online. With the fare class rules with regards to frequent flier mile accrual, they are really messing us over when we have to call in to book an L fare (at 50% accrual) because the system can't seem to handle doing online ticket changes appropriately.