It has been a while since I last had a new Payflow Pro account, so I don't recall what it did with live credit cards. What is usually done is to use a test number (usually 4111 1111 1111 1111, which is a fake VISA number) with a made-up expiration date in the future. If that doesn't work, then something is wrong.
BTW, there is supposed to be a huge problem with the Payflow Pro driver and AOLserver, resulting in random crashes, so keep an eye out for that. If you don't experience any crashes then maybe they have fixed their libraries. I don't recall the exact details but you should be able to search and find threads on this.