Aw, man, I overlooked that and grabbed from 1.25. Judging by the past release schedules, which look very predictable, 1.26 should come out in March, up to a month and a week away. To save me rebuilding thius as 1.24 now just to see 1.26 come out soon and then be building it, how about I leave it as is for now. I plan on a fairly long testing period for the new gtk2 libs and will wait on atk-1.26 before updating gtk2 anyway.
I agree that only official releases should be used in production extensions, especially those that many apps depend on like gtk2. I hope this sounds agreeable.