Problems with the "ellipse split" plugin




I am using the Ellipse Split plugin to analyze this kind of image:

The plugin has already been run on the image and, as you can see, it does not recognize all the particles. The shape of the region defined by the particles that are not recognized is either circular or elongated (rectangular probably).

I have been using this plugin for some time and I have had no problem with many of the analyzed images (I have seen this before, once or twice), but today this happened on 5 images out of 5 analyzed. This is happening on 3 different computers. The images are large, around 30000x10000 pixels, containing 15000-25000 particles.

Any ideas of why this could be happening?

Thanks a lot in advance,