Whilst playing with my bad-behavior callback function, I noticed something quite crucial; plug-ins load in alphabetical order!.

I noticed that every time a new version of BB is released / upgraded I had to re-paste my callback function into bad-behavior-wordpress.php - DOH!

To get around this I decided to create a new plug-in called linickx-bb-callback.php, but I noted that the counter wasn't increasing. Changing the file name to aaa_linickx-bb-callback.php fixed the issue, sweeeeet!