No. You were asked to pay a fee because you signed up via an IP address (or more likely a subnet) that was previously associated with spam. The fee is only calculated when you register and not when you post/login. Paying the fee will not stop you from getting banned in the event that you break the rules.
It's actually not even necessarily that that address was previously associated with any spam. All tor exit nodes are subject to evil points.
See the discussion in this thread:
https://bitcointalk.org/index.php?topic=711968.0