You'll be glad to know that I have, finally, found a solution for Valley fort bug that used to ruin many players' time and tough work!
Ok, lets talk about it. As soon as you fall down the valley, immediately, without wating for even a single millisecond, press the BACK + LEFT keys! And that's all! You won't be bugged at all!
Go ahead, try it for yourself and tell me if it doesn't work. This worked for me many times!