Just asked a TA about purchasing a ticket as early as possible and got the following reply. I don't follow - doesn anyone here know what is meant? (Maybe it's just a language thing).

"As you understand that a travel agent can make a booking and sell ticket approximately 330 days before depend on each airlines' computer system. According to the airlines' rule, a one year ticket is valid from the date you issued a ticket. For example, if you issued a ticket today, Feb15, 2005, the last departure may not be later than Feb15, 2006. One you depart, the one year validity will be start from the date of departure. This is very common on the one year ticket. The problem is it will depend on the airport check in counter weather they accept. And nobody can answer now even the airline itself. If you want to do this, we have no problem in issuing such tickets if the airlines agree. So we DON'T suggest passengers to buy long time in advance."

I don't understand this - if you can book and issue your ticket and you are holding it in your hot little hands, then how can someone at check in reject it?