It seems to be a frequent problem, and it may be caused by a variety of things. Try printing again, maybe even a couple more times. You can also try changing the printer settings. Another possibility, if you are dealing with text, is to copy and paste. If that doesn't work, the problem may be that the web site is constructed with frames.
Some Web pages have frames that are difficult to perceive.
If that is the case, try clicking anywhere in the frame that you want to print. Then print as usual. You might also try the old copy and paste technique. Copy what you want and paste it into a word processing page. Thanks to David Ibbetson, Glenn Ibbetson, Glenn Kersten, Mickey Laskin, and Thomas Gore for help with this question.