We installed Woothemes Paypal Payments Advance
We contacted Woo plugin support , here is their response to us
Your store is configured correctly. And your theme is entirely compat with WooCommerce thus it's not display errors messages in all cases.
We activated TwentyTwelve and did a test purchase. On the pay page we see this message from PayPal Test OK
Our plugin is working fine.
When in doubt, activate TwentyTwelve. In our experiences theme developers aren't always thorough PHP programmers.
What do we do know?