It's not lag, it's a synchronization issue between all the PS3s playing in the same room, which is why bombs appear in different spots on everyone's screens. The problem is that this placement is irrelevant, the bomb will only detonate if you actually hit the spot where it was placed by the one who launched it. The ships also behave with prediction calculations made by your PS3, then these predictions are corrected with the next packet of information. I guess the problem comes with the fact that bombs are programmed to appear behind the ship that launches it, not in the actual spot where it is placed, when playing on the internet. Or something like that. It's weird that mines work a lot more times than bombs though, you would think they would use similar code, just a different timer and area of effect, physics effect and graphics effect.