On all of your Products that are Priced by Attribute, they are ALL set with products_price = 0.00 correct?

If so, run the following in the Tools ... Install SQL Patches ...
Code:
UPDATE products SET products_priced_by_attribute = 0 WHERE products_price = 0;
Have you done any customization to Attribute Grid Layout other than install it?

I have Attribute Grid Layout installed and cannot reproduce a screen with any product set to Priced by Attribute that shows the $0.00 next to the Attribute as you have it ...

See if there are any changes when you run that SQL Update in the Install SQL Patches ...