During the afternoon of December 24th, 2011, I along with four friends found this bird just outside Bang Krang Camp, Kaeng Krachan, Thailand.
According to Birds of Thailand (Robson) the only Bush Warbler which occurs in this part of Thailand is Spotted. However, our bird seems to lack spotting on the throat and barred undertail-coverts. But hard to be sure because of poor pictures.
I hope someone can share their view on this bird.