Windows .exe Harvester reaches WAY too far

[Express]

I've no idea if this is the right place to post this, but I have a Harvester in my server and that thing reaches to almost double the specified 3x3 square and I've no idea why, its set up to run as shown in the video on the ftbwiki.org page for the item, but its chopping down things I don't even want it to touch.

 

[DZCreeper]

It will reach a little further if a tree grows to chop the leaves.