Hi there.
After installing the module and adding a rate (using your example rates 10:5.25/1, 15:64.25, 20:75.50, 30:100.00, 999999:10%) the checkout is no longer continuing after Step 2. If I disable the module, checkout works.
Any ideas? Below is a screengrab of the rate I am trying to enter.
screengrab of the rate I am trying to enter - Screen Shot 2012-07-26 at 5.56.32 PM.png (72.92 KiB) Viewed 1355 times