Hi
I've the same problem and I've solved it just like you say, but I've noticed that when you edit the name of a carrier marked as "free shipping" something really weird happens:
- The ID number changes
- In the database the original item is marked as deleted
- In the database appears a new row with a "new" carrier, that shows the edited name.
I just wanted to explain this because it's seems to be really a bug, and if the "free shipping" slide is creating all these problems, maybe it'd be better to disable it at all.