When I export from keynote as PDF the pages have borders around them when they were not there on keynote...help !

I create slides in keynote and save them...then export them into a PDF format, then when I go to print and see the preview there are very noticable borders that I cannot seem to get rid of. If I press fill entire page then it cuts off some of what is on my page ! Also, some things come out differently (eg overlaps of shapes etc) that were not visible on the slide in keynote. Please help me !!