V8i SS3 Printing with Design Script - One Cell is causing a problem for the entire plotted sheet, affecting other elements

I have a drawing which does not plot correctly. I am using a client-provided design script which "drops" elements to make them look like they are screened. The design script basically searches for elements by level and if the elements are within a certain range (for instance, between level 2 to 9), the design script is supposed to change the linestyle of these elements to a dashed linestyle, which creates the effect of screening back the element. This is kind of a strange way to screen back elements, but that's the way the client does it, so we must comply.

Anyway, my drawing is exhibiting strange behavior, and is screening back selected random elements that shouldn't be screened, and basically screwing up my drawing. I managed to somehow pin down the problem to a single cell in the drawing. If I delete the cell, everything is great. If I re-insert the cell, again, all is good. I have concluded that something was wrong with that cell. So, good riddance, delete the cell, put in a new one, and all is good.

However, this happened again, weeks later, on another drawing. Only this time, it was a line, not a cell. Different symbology, same problem. 

Now I'm worried. Especially because it takes me a full day to narrow down all the elements in all the reference files, to find the culprit. I don't have time to do this. I just can't understand how two apparently identical elements can exist in a drawing, right next to each other - one causes the file to print incorrectly, and the other does not. All I have to do is delete the "bad" element, and everything else in the plot is good! What could cause a single cell to mess up everything else? It sounds like cancer, doesn't it? I would be more than happy to share my design file and design script with anyone who cares to explore.

Thanks!