Hi,
This bug is really hard to put in words. Let me try to describe the steps I took so that you can recreate it.
First, create a product call Mix Food
You can leave everything as default. Just fill up Products Name as Mix Food. No need put product description/image.
Second, create Option Name
Now, create 3 option names: Poultry, Seafoods, Vegetables. All 3 is using Option Type checkbox. Set sort order for Poultry to 1, Seafood to 2 and Vegetables to 3.
Third, create Option Values
Then key in values for above 3 option name. I created 4 values for each option name.
Poultry: Drumstick, Chicken wing, Egg & Thigh.
Seafoods: Fish, Prawn, Crab & Squid
Vegetables: Tomato, Bean sprout, Spinach, Carrot
Fourth, add attributes to product Mix Food
After you have the option name/value pair ready, add all the attributes you created above to the product Mix Food. Leave everything as default except for Price field.
Poultry is +$1.00
Seafoods is +$2.00
Vegetables is +$3.00
Now.... the testing begin
Go to the product information page at your online store. You should see the 3 options on the page with Poultry on top, Seafoods in the middle and Vegetables at bottom.
Try to add 1 item to your cart with this selection...
Poultry - Chicken wing
Seafoods - Crab
Vegetables - Bean sprout
Everything is good.... until you continue shopping and add another item with this selection...
Poultry - Chicken wing
Seafoods - Crab
Vegetables - Carrot
Your previous selection is overwritten by the second selection and merge together.
I hope someone will be able to duplicate the same problem I faced now.
I tested this on clean install of version 1.3.8a



