as above your rice has to be in boiled temp. and did you make sure that all the rice are covered with your stock? raw rice do not cook very well in oven. Maybe you should boil it.
next time dont throw it all away, just add more stock to your dish and cover and boil on your cooker (high)for at least 15mins. then place it in the Oven.
other wise for step two (on the guide)..... cover and boil for at least 15mins on the cooker, dont open the lid, otherwise the rice would not cook.
then you can place it in the oven for 55mins.
but i was just thinking instead of putting in oven you could probably simmer on the cooker med heat for 35-40 mins, stirring each time.