I recently transferred an FCP7 project from one drive to another. Everything seemed to go smoothly, all data was accounted for on the new drive.
During the inaugural new-drive-project-opening, it appears the program has smashed the 16x9, 1920x1080 timeline into something 4x3. First checked my source files, and there was no funny business, they were still 1920x1080 ProRes files.
Next checked sequence settings. The frame size and pixel aspect ratio were both at 1440x1080, 23:98, ProRes422. Not 4x3, but also not my previous settings, so I corrected it (1920x1080, square pixel aspect ratio, ProRes422)
The files are also still 1920x1080 in the FCP Browser, look fine when dragged onto this timeline. The issue is with the existing reference cuts on this timeline.
I've tried reconnecting media on the timeline to no avail (nothing changes in its canvas appearance).