I think it has added like 2.00 charges to me before for 'extended download' services.  In which case there would be a charge in your cart, and cc required unless you remove that option from your cart.  It's not that hard.  

As other people have said, a CC is not required for a service update alone.  Period.  

Don't want to come off as rude, but if you are reading the cart at smith micro wrong, and missing something there, it's possible you missed something else somewhere too.

Ever hear the phrase:  You catch more flies with honey?

If you were sooo looking forward to it, why not at least give some of the solutions offered you a try?  

For the record, due to a completely separate issue, I just downloaded the latest service release from smith micro.  My serial number allowed me to place it in my cart.  NO credit card was required.  This was literally 2 minutes ago, the download just finished.

I am:  aka Velocity3d