100% coupons and shipping fees

[wbyers]

Okay so I work for a company that is trying to integrate shipping fees into a system where we give customers 100% off coupons to switch classes, at the moment it seems that we cannot change the shipment method to our free shipping even after 100% of the price is discounted. Is there a way we can set this up without a massive amount of code? Or will we need to use an override plugin to do this?
We have two shipping methods one for amounts above $50 and up thus no maximum and one for between 0 and $49. We are using the virtuemart weights zip and countries method for the both of them.

For added info we are also using the virtueplanet onepage checkout with the reload payment and shipment method turned on. Yet even with the order discounted down to 0 we still pay a five dollar shipping when we should have been reloaded to the no charge shipping option. Is this a Virtuemart problem or is this one VP?

We are currently using the shipping fee as a method to charge a processing fee orders above a certain amount. Is there an easy or well known way to do this other than what are attempting to do with the shipping fee?

[seyi]

You can setup a 3rd shipping method, standard shipping, and set the maximum order amount to 0.01 with shipment fee of 0.  It should only show when order total is 0.