tax calculation in zoho CRM broken?

tax calculation in zoho CRM broken?

Hi Everyone,

Quick question- Why is it when I create a new invoice, add a product with a unit price of 0, but a list price of $10.00, I'm able to calculate the correct tax percentage for my area (7%, $11.40).....

but when I add a product with a unit price greater than 0 and a list price that same $10.00, I'm unable to calculate the tax? (tax values stay at 0)

anyone?