Product Variant Error in Shopping Cart

I have one product with 4 price options. $25 $45 $60 $75

In order for the product pricing to work as desired, the product value is set at $25, and includes a variant with 4 price option choices holding the values:
$25 (+ $0) (set as default)
$45 (+ $20)
$60 (+ $35)
$75 (+ $50)

You assisted me in stripping text from the value shown online 4 months ago.

Until now, the product has been working well. However, I backed up the site today to my local server, updated from v 2.0.0 to 2.1.1 and have found that the product is not working properly.

If I choose the default ($25 minimum), then proceed to the shopping cart, I receive the following message: ! The Product Quotation Received: $25 is not available.
However, the product is indeed within the cart, and if I log into a testing client account, the message goes away.
Remaining logged in, I emptied the shopping cart and added the $25 again, proceeded to checkout and once again, receive the same error message.

All other values ($45, $60, $75) work fine.

I am suspecting the upgrade demands a different procedure in order to create the above product type circumstance.
Can you advise what I have to change in my original setup to make my product work once again.

Thanks in advance for your assistance!

Hi there,

It's because you disabled the "Display 'add to cart' button for free products" option in the main configuration (system>configuration>main>product).
It's know issue we are working but enabling it should solve your problem.

Excellent, that did the trick! Thanks!