That's why I said earlier when saying avast version 5.0 isn't going to have Heuristics as there is a fairly clear definition of what Heuristics is. So what avast intends (more a behavioural function from what has been gleaned on the forums) wouldn't fall within that definition and neither would the description of ThreatSense.
So the definition of heuristics hasn't changed whilst you weren't paying attention
or I wasn't paying attention either