Okay, fair enough. So I've created a fluid cache by selecting my two fluid containers and going to Fluid nCache > Create New Cache. So then I sat back and waited whilst it cached for the next 1 1/2 hours. I could see both explosions happening frame by frame as it did its calculations, but after it finished when I moved around on the timeline it only shows me one of the two explosions. And when I play the animation from the start it doesn't do anything either. In short my main explosion has disappeared!!!
Does anyone have the slightest idea what's going on?