I find that the availability tends to come and go, at least judging by ExpertFlyer. Whole weeks will show 9s next to every flight, and a few days later nothing will be available.
I booked a one-way BOS-DUB via the BA call centre last week... EF showed 9 seats in business, but as soon as the booking was made it dropped to 0. Seems to indicate that while EF might be correct in indicating whether or not seats are available, it may not correctly display the number of available seats.
Keep checking - and good luck!