The trees that cross the ravines in blightwood have a tumble check to cross them, but I do not think that the tumble skill points of my character are being applied, and it is instead just a straight D20 roll. I wear +4 tumble boots and I consistently see +0 instead of +4 to my rolls. I dont wear armor. (Personally I think it should be a Dex check not a Tumble)
While I'm at it, I'd like to complain that these logs are one-way, but if you can fall off the log at these points (unintentionally), then one ought to be able to voluntarily jump down as well. Consider adding a way to voluntarily go back (jump/fall) once youve crossed the log. Players should be able to retreat from their position, even if its at the cost of falling down