Csv format – CSV import of truncated data

I use Mathematica 10.0 and the Import function to load a list of points from a CSV file. However, when I test the length of the file (which should exceed 18,000 points), the data seems to be considerably truncated (about 16,000 points). Deleted data is random and not simply deleted. I've tried to change the size limit (as this is an option when you import) but it does not seem to do anything. Any ideas why this could happen and how can I solve it?