When an official 1.5.1 Forestry is released we'll be updating to that.
We updated Forestry to a newer beta version. I have updated all the links. This update will not require any Forge changes, just download the new Forestry and delete your old one.
This will help with some lag and stability issues, and fixing some of the features which weren't working. You won't see a lot of changes, as most of it is behind the scenes, but will improve your play experience by a lot.
All you have to do from there is download the Forestry I posted and drop it in your mods folder.