Checkout with $0 amount

[JanB]

I am sorry if this has been addressed somewhere else, but I was unable to find it.

I am on vs 1.4.2.5.

I would like for a customer to be able to checkout with $0 amount for downloadable products. I am using Paypal, and I go to checkout, I enter my customer info (I want my customer to create an account), and when I enter in my login info, I end up back at the home page.

In preferences->products - I have 0 on Minimum purchase total ... -which says a 0 disables the feature, so how can I have a checkout and email of downloadable product for $0?

Thanks.