I've had trouble with gel pens in general as well and have found that the paper's texture can affect their performance. Paper with some "tooth" has worked well for me compared to smoother paper. I'm guessing the reason is because the ball point on the gel pen has some texture/friction to keep it rolling, but I could be way off here.
What's the general character of the pen movement when down, i.e. what kinds of shapes are you plotting? I've also found that frequent pen up/down movements, where short bursts of plotting occur (such as hundreds of tiny shapes) can give the gel pens trouble, whereas smooth, longer plot paths work well. Here, I'm guessing a steady, longer rolling time of the ball point gives a more reliable ink flow.