Having looked at this, I think I have a solution. I've tested this as far as I can (On my dev install I can't go beyond the PayPal payment section).
I've created a setting now that let's you choose your separator for the values and the system checks that. My tests show fine. It's my guess that your contributions are going into the 'unconfirmed' section in your tests.
Once I've marked it as confirmed the correct amount is added to the banner.
Let me know if you want to give the code a test as per the PM I sent you and we can see if we've got a fix for you.
Matt