I began experiencing problems since Sunday afternoon; I even had to call the 1-800 line to cancel some reservations that were on hold. I thought I just had a disgruntled employee, judging by her tone, but now I see she must have been inundated with calls.
Like most, I lacked about 13K miles to get Plat, and so I made a few reservations until I chose the one that worked best. I suspect many people were in the system doing the same. I finally found a routing to my liking, but then could not apply a credit (Flight Change link), and so I had to call the 1-800 number again and was connected to a woman with a great attitude that helped me out.
Another weird thing I noticed... if I did a fare search via the calendar, it always priced out differently than the regular Continental Reservation search, yet the dates, class, flights, etc. were exact to the dot.

Wonder what was going on there? It was lower using the fare calendar, BTW.