Multiple file pairs in the same Project?

I just started using WinMerge and find it quite useful as a free tool.
In reading the manual about Projects, the text makes it appear that, when saving a Project, all open files (or, pairs of files) are saved in the Project. However, when I look at the created Project, only the last pair of files opened are saved.
I tried manually updated the Project to include two <paths> tags, but when I opened the Project, only the last <paths> element was used.
Am I doing something wrong, or are Projects limited to only a single pair of files?
In reading the manual about Projects, the text makes it appear that, when saving a Project, all open files (or, pairs of files) are saved in the Project. However, when I look at the created Project, only the last pair of files opened are saved.
I tried manually updated the Project to include two <paths> tags, but when I opened the Project, only the last <paths> element was used.
Am I doing something wrong, or are Projects limited to only a single pair of files?