Yes, I have experienced the same problem!
It seems to depend on what Quandrant Type you choose to generate. With the maximum set to 255 and I get:
Mid-Life: This works. I get lots of star systems.
Cluster: Doesn't work as well. There's always a blank area around the four borders of the galaxy without any systems.
Galactic Edge: BAD! Get nowhere near 255.
Spiral Arm: BAD! Most of the stars form a rectangle on the outer edge of the quadrant window, with not many stars in the middle.
Grid: BAD! Get a quadrant with stars neatly arranged in a grid, but nowhere near 255 stars.
Ancient: This works OK. Get lots of systems.
So try using Mid-Life or Ancient.
Does anybody know how to fix the other quadrant types?