Sonic, are you aware that Rigs created using 4.x and beyond won't be compatible with 3.x?
Now that you mention OS versions, I would be nice to have a copy of version 3.x and 4.x. in case I ever need to roll back. Is there a place I can get those? (They don't seem to be available for download)
I can send you the latest 3.x and 4.x versions if you PM me your email address.