Basically, at least 2-3 times per match, using Grendel+Rapid Fire 3, clicking the mouse button to shoot will not do anything but only once. It's like the mouse click was not even processed in the game, or perhaps I pressed the button when the delay was still in effect, though I imagine that there is some kind of queue that would prevent this.

I would really like for someone to investigate it, however it may be hard to reproduce unless you are actually facing an enemy.

Why do you use rapid fire with the Grendel o_o

Its more pointless than Aim Enhance + Grendel.

Why, because Rapid Fire counters to a degree the fast pace of the game. I mean, I have so many players coming at me at the same time, I need to shorter delay between shots.

I think coolguy's argument is that that module slot would be better used with a lot of other modules. But that's for another thread.

I have encountered your problem as well. Sometimes I'm trying to take someone out and I miss a burst I could have sworn was on rhythm; then I die.
Because the Grendel's got problems.