At 72dpi your image would have a physical measurement ( inches or centimeters of about 36 inches by 27 inches - Im guessing your layouts arent that big
All you need to do is manually change the resolution.
In Photoshop, all you need to do is go to Image > Image Size (uncheck Resample Image) and change the resolution to 300dpi, or in DIP and I am guessing other programs you should have an Image Size option that allows you to change the resolution. If you let me knwo which program you are working in I can be more specific.
Some photos open by default at the 72dpi reading. I have never found an answer as to why.(anyone else?) I can open my Nikon photos in any program and they automatically open at 300ppi but my mothers Olympus always opens at 72ppi and I have to manually change the resolution.
HTH
BTW Read this article to learn more about how resolution and pixel size are interelated
http://scrapbook-bytes.com/cgi-scrip...icle_285.shtml