Yes... you have 'none' selected as your payment gateway.
The powerstore is not designed for offline processing. It doesn't store credit card numbers, so there is no reason to ask for one if you don't have a payment gateway defined.
You'll need to manually update the checkout process to do what you want. I'd suggest minimally using the latest version of security assist to encrypt the CC number with RIJNDAEL encryption. It can be unencrypted for processing but is nearly impossible to decrypt without the encryption string which you can store outside of your database.
I'd also make sure to delete it entirely after processing to be extra safe.