have a look at the cells, do they have fill or shading?
Often civils use cells are taken from imported Autocad files and some people still shade instead of using fill.
So a black dot might be a huge shading and taking up a lot of time to display.
If you find a 'black hole' like this just edit the cell and use fill instead of shading.
Afterwards you can use the global cell replace to exchange all the cells placed