Hi, i'm unable to reproduce the problem here using your object: i create a new scene, merge the tree and assign it to a Forest object. The alignment seems correct, using the pivot of the object (same result as shown in my previous post).
What Max and Forest version do you use ? I used FP 4.3.4 and Max 2015.
Anyway, i see this tree comes from the XFrog library. It's true that exists a problem with objects from this library. You can see a discussion here
. But this case is different, if the object is already attached and the pivot aligned correctly.