I keep plugging away with them. I've had fine luck with e-tickets through them. The one time I had a significant problem was when I had to change my return flight. Despite the fact it was a full-fare ticket, the hassle I had to go through was amazing (on hold for 5 minutes to talk to someone, on hold 10 more minutes transferring to someone else, and on hold 15 more minutes while she figured out how to change it).

And to boot, they changed the ticket for the wrong day. Fortunately the CO counter agent was nice enough to fix it when I showed up at the airport. She did indicate to me that "this sort of thing happens all the time with them". Oh well.

I've since amended my procedure to only buy through COOL when I'm 95% sure I won't have to change the ticket.