Why are there certain pages where paypal does not allow payment via paypal balance.

Description

I want to use paypal balance to pay for purchases. However more and more I’m finding pages that when I go to paypal checkout I see something like this: The problem with the image above is that there is NO option to pay with paypal balance. When asking the merchants they are puzzled and usually tell me that they see the option. So I’m guessing that the problem is between me and paypal. Can anyone shed some light on this problem. Just so it’s clear, I do have enough money in the balance for the paypal transaction. Regards, Ariel.