Hi,
This Is Mani from Bangalore, India.
Open a word document then type few lines (2/3) then observe is it happening same in word also..?
I thin it is set for Double space, wee need to chnage to single space. or else chech this web link -
http://www.tchp.org/miscellaneous/KeyStrokes.html
I have attached a screen shot, try, still any issues report back.