options error

v2.0 business, jj2.5.8

i have created an option for a product with 2 choice, one at no additional cost.

when selecting the default no cost option, this error displays in the mini cart:



if you chose the option with an additional cost, it displays ok

can be seen live at:
www.plumbing-deals.dreamhosters.com/inde...r-1e-steam-generator

You should turn on the option "Group options with products" in the Checkout tab of the configuration.

that was it!