Gary (and Jim),
When you open a "forum" and you see the list of threads in that forum, if you will scroll down to the bottom of the page you will see a block titled "Display Options." On the line that says, "From The", click on the drop-down list and go to the bottom and select "Beginning." Then move your pointer to the right and click on "Show Threads." You will then be able to see all of the threads that have ever been created in that forum and, as Jim said, there may be more than one page. Once you have made this change it seems to apply to all additional forums that you open during your current session. The forum default for this parameter seems to be, "Last Month." You can change it permanently for your own profile by going to "User CP" and clicking on "Edit Options" and going about halfway down the page to the window titled, "Thread Display Options." At the bottom of the window you can change the "Default Thread Age Cutoff" to whatever you prefer.
Hope this helps.