Your web browser will usually try to open PDFs in the same window you are viewing the website in.

After clicking on a PDF link such as a catalogue or seal datasheet, you might be presented with a blank window while your browser downloads the PDF you have selected. On a 56K internet connection, this can take quite a while.

A better option is to right-click on the file (or control-click on Apple computers) and select "Save Target As...". This will allow you to save the PDF file to your hard disk without trying to load the PDF in your browser window.