Problem with generating posters


I am trying to print a poster-sized PDF file from Powerpoint 2007.  The poster size is 90 cm wide by 60 cm tall.  When I create the poster, these very fine white lines are present in the PDF file that span the image horizontally.  These white lines overlay any images or text the line happens to cross.  There are usually two or three lines spaced vertically down the image.  This occurs when I use a Custom Postscript Page size and enter 24 inches width and 36 inches length (for some reason the printing on the poster is rotated off the edge of the poster when I use 36 inches width and 24 inches length).  I also print in Landscape mode.  

This does not occur if I choose 36 inches width and 24 inches height, and print in Portrait mode.  The poster is then printed correctly without lines but rotated by 90 degrees.

Also, how do you ensure that the fonts are embedded in the PDF?  Many systems don't have Calbri truetype font, and even if  I click Embed All Fonts, some printers can't print the Calbri font.

Thank you!