Emoncms export data problem

Hi all,

When I export data from Emoncms.org for 24 hours with 1 hour step. the csv file contain only 19 lines with 3600 sec. step. I tried several parameters  including  changing the time zone. Changing the time zone from -3 (Chile) to 0, the file contain 26 lines.

How can i export the right number of data?