No idea on the booking snafu, but can help on others:
Originally Posted by lowlyblue
Incidentally, if there is no award availability on the website for a flight, then am I right in thinking you won't be able to get a 241 (plus award) ticket for that flight either?
Correct - you need to find a flight with two award seats in the cabin of your choice.
Originally Posted by lowlyblue
Final question: can you book separate classes for outward and return when booking a 241 ticket?
Correct - I've done a couple of "mixed class" twofers