Wrong resolution when restart

Hi, first thanks toastyx for cru, its great

I m on windows 8.1 x64 and have a GTX 570

Basically I use the pc as htpc conected to my HDTV

So I use cru to fine tune the movies refresh rate... 23,976 etc...

So i don t overclock the tv and don t have to use pixel clock patches

My tv is 1366x768, Windows say native is 1360x768 but on the sheets says 1366x768!and with this resolution I get perfect 1x1 pixel

Everything is good my refreshes a very good Tuned I get audio from hdmi...
But everytime I restart the computer the resolution is changed to 1024x768, that is quite annoyng... because everytime windows starts I have to change the resolution l
Doe anyone knows why this happening? And how fix it?
Thanks