Got an email from UA telling me about a schedule change. Thinking that this was one of those two or three minute seasonal adjustments, I took a look, and lo and behold there was no time change, rather, one of my O/B flight numbers had changed. What had also changed was that I no longer had assigned seats on BOTH of my O/B flights (SNA to IAH, IAH to RDU). Soooo since this was CO metal, I went to the CO preview site and plugged in my UA record locator. Voila! All of the flights appeared, except SNA IAH (the one that the flight number had changed on). I was able to re-assign a seat on the IAH RDU leg no problem. I tried to update SNA IAH leg on .bomb but got an error message. I called UA and they said all they had to do was update the PNR and then I could select a seat. But noooooooo. So I called UA back and they were able to pull up a seat map on the CO 738. I asked for exit row and was told that was reserved for 1Ks as I was blocked on her screen. (I'm 1P) I told the CSR that this is obviously incorrect b/c I was already seated exit row IAH RDU. She called Continental and got it done. Very professional but obviously a bit frazzled. She said they had been told this was customer day 1. Moral of the story? Make nice with your CSR and you will get the job done. Overall not a bad experience, but shows that we are in for some glitches in the days to come.