This information was given to me by a customer and it works great.
If you open your 2007 tool library with any text editor and search for a string "ID=STRING", you will find your milling
tools section. That is actually the issue! The header for the tools table should be "ID=INTEGER". So if you
edit the tools library and replace "ID=STRING" with "ID=INTEGER" you'll be able to import it fine.
I hope this helps everyone