Not sure i understand your problem - but i'll try to help.
When you print is it cutting off directly proportional to those lines? Many printers have SET in Stone limits as to how near the edge of the paper they can print. I have an Epson that can print borderless (all the way to the ends) - but this is more rare than common. This may be your problem.
You can always look for options like "maximize print area" - many printers have this. However they'll still want typically at least a quarter of an inch of blank space all the way around - and a little more on one side which is where the roller's 'grab' the sheet to feed it through.
Hope that helps - oh - and one last thing - you can do it the old fashioned way which is to print onto 11x17 with crops and cut down.
Hope that helps a bit.
// jayse
Ultimate After Effects Video Training CDs
Free Photoshop CS Video Tutorials