Download numbers inconsistent for different periods

Hi all,

I am interested in download numbers for a particular file over the last year. I have found that I can get two numbers for April any May 2015, but not for the following months. Also, a custom date range from mid-march to mid-may returns a number lower than the one for April alone. The full-year period does not contain the file in the download list, but shows 376 downloads in total.

So, does that smell like a problem or would you except it from the way Piwik works?

I mean, could it be that the download is dropped from the reports because it was too unimportant over the course of a year?

Or, is it expected that different period reports give different numbers?

If not, what might be the likely cause (and fix) for this?

Thanks!