Information and tables to encounter slots can be found here.It works with ROMs, therefore there is something you are doing that isn't correct. Recheck everything, especially the date (year month day).
My Question:
How exactly do you use encounter slots? How do you make sure you land on your delay/frame to get the right pokemon? If there's a guide that explains this, please give me the link.
Basically, you would right click a particular frame on the the RNG reporter and it will give you the encounter slots for it. For example, say that a particular ditto appears on encounter slots 4,5,6,7. You would search for the frames that would have those encounter slots in the sweetscent (grass/cave) section.