I don't have invisible entities spawned. All I have spawned is a few spheres at random positions (in a solar-system type arrangement) and they're pretty small, and all are visible. I've verified this.
I set mouse_range to ridiculously high values, ranging between 1000 and 10^7. The mouse_range seems to have no effect.
As to panels, I don't have any at the moment.
On a side note, I currently have no level loaded (only a blank one using level_load("");). Maybe that has an effect?
Edit: Thanks for the replies so far
Edit 2: The entities spawned are a maximum of 30'000 units away from eachother. With a mouse_range of 10^5 I should be able to get all of them, no?