Be happy, or may be not, because it is not that you are overlooking the right options in the program. The option just does not exist in all versions of QuarkXPress prior to version 6. You cannot print high resolution images directly from your QuarkXPress software to your desktop printer unless you have QuarkXPress 6.
The reason some pictures look better than others lies in the format you are using. TIF images usually look better than EPS ones with QuarkXPress because of the way the format itself is structured. I won't go into details, which you really don't need to know about, however, whether you save your image as an EPS file or as a TIF file doesn't really make a difference (if you are talking about a photo and not about a non-photographic image). The information contained in the files is the same; but, because of the way those two formats are constructed Quark will render them differently.
This might make you think that once you go to press, your pictures will look better in one format rather than the other, but that is not true. EPS files take up more space than TIFs therefore there is really no reason why you would be saving your images in EPS format (again, I am not talking about non-photographic images). There are also other reasons, but they are not important at this time. There are many discussions about these two formats and their use in the About Desktop Publishing forum and if you want to learn more about this subject you can go and have a look.
Going back to how to print layouts with QuarkXPress, if you need to print a proof or you want to see how your images will actually look, your only option is to make a PDF.
The way you make a PDF differs slightly, depending on the purpose of the PDF. Follow these instructions for How to Make PDFs from QuarkXPress 4.x and 5 for your desktop printer. Note that to be able to make PDFs of any kind you need to have third party applications that can make PDFs, such as, but not only, Adobe Acrobat Professional full version (not just the Acrobat Reader). In the PDF tutorial I am using Acrobat 4.0. The procedure described is valid for Macs. It won't change much with PCs, but it is slightly different.
In QuarkXPress 6 everything is much easier. You don't have to make a PDF if you want to print your layout with high resolution pictures. All you have to do is to right-click (or Alt+Click) on your picture and a menu will appear next to you cursor. Go down to Preview Resolution and select Full Resolution. You will be able to view and print your image with its actual resolution. If you are trying to print to your desktop printer you will still need to convert your images to RGB, but it is much simpler with QuarkXPress 6 than it is with QuarkXPress 4.x and 5.
