I'm having trouble with the Juggler trophy in Resistance 3. This is the one where you have to burn, freeze, and poison 4 enemies. I thought I did this successfully 3 or 4 times during my first play through, but I checked the counter for this trophy and it still shows 0/4.
Here's what I was doing: I would first poison a Ravager, then set him ablaze with a molotov, then freeze and shatter him with the cryogun. Am I doing something wrong?