PP Sandbox Always Approves Transaction

I - wondering what I can do to fix this or if anyone else has had this problem.

It seems that on my checkout.php page I can enter pretty much anything and PP Sandbox will approve the transaction. I have created a test user and am entering the CC info and the wrong expiry/address/etc. and PP will approve the transaction and my page returns to checkout_success.php.

The weird thing is that the transactions are actually posting on the PP test site too.

Anyone else experienced this?
Thanks

Try entering an invalid credit cart number and make sure that the expiration date is a date prior to today's date(10/10).

This is interesting. This is the response from Paypal Merchant Technical Support:

Thank you for contacting PayPal Merchant Technical Services.

The Sandbox is designed to easily allow merchants to test their website and scripts without real money changing hands. As part of this Sandbox does not auto-decline mismatched credit card information like the live site.

Sincerely,
Bryce
MTS

What is the point of 'registering' the credit card info and name on the Paypal Sandbox Seller account then?

In my testing, entering an invalid credit card number that is not registered in sand box should fail. Do you have a link where i can test a sandbox transaction.