Which one is reliable? CSV vs HST/FXT

 

I use Tickstory to download data for testing in MT4 Strategy Tester.

When I download the data in CSV format and import them into MT4, the results in "Every Tick" model and "Open Prices only" model are the same, with a tiny difference.

But when I download the data with Tickstory's "Export to MT4" feature the results are not the same for "Every Tick" model and "Open Prices only" model.

These two methods have not the same results.?!?

The tests have been made on the following:
EURAUD
EURGBP
EURJPY
EURUSD
GBPUSD
NAS100
UKOil
USDJPY
XAGUSD
XAUUSD

The downloaded period setted in Tickstory is "01-Jan-2010" - "30-Jun-2015".
The period tested in MT4 is                          "01-Jul-2010"  - "30-Jun-2015".
The imported CSV's from Tickstory to MT4 were for M1, M5, M15, M30, H1, H4, D1.
The Exported data from Tickstory to MT4 were all timeframes(M1, M5, M15, M30, H1, H4, D1, W1).
The tested periods on MT4 were H1, H4 and D1.
The tester runs offline.

Which results are reliable? CSV or Exported to MT4(HST/FXT)?
Which results should I use for reporting and research?