That was it. I turned on the “Limit forum display to within WP loop” option and now it works correctly. I guess I don’t know the WP terminology well enough to make myself clear. Usually the forum displays within the normal content area of the WP page, with a sidebar on the right. Instead of this, the forum was displayed by itself across the full width of the page, the all the rest of the page was displayed below the forum with the content area (where the forum should be) blank.
I remembered, once you said it, that “forum – integration – page and permalink” was what I had used to fix the problem last time. That was several months ago and it suddenly happened again. Seems like the options in that section are different now. Was anything changed in the last update that might have caused this? Or could it have been caused by the WP 3.6 update or an update to some other plugin or theme of my site?
Thanks,
Dave