My b2evolution Version: 3.3.3?

Sometimes when I ban someone for spamming my blogs I get the following message:

* Remote error: Invalid return payload: enable debugging to examine incoming payload (XML error: junk after document element at line 2, column 0) (2)
* Failed to report abuse to b2evolution.net.

How/where do I enable debugging? It wasn't bad today, but sometimes there are 50-100 hits from one spammer in a 24 hour period.

Also, I downloaded what said version 4.03, but the version numbers at the bottom of my dashboard page say it's 3.3.3 Which version do I actually have??