When you import an Open Clip, the media it references is still imported using that media's Format Specific Options: a referenced .mov is imported using QuickTime settings, while a referenced .dpx sequence is imported using DPX settings.
If you cannot access an Open Clip, it is probably because its different channels are of mixed frame rate. Use the Rate box to assign a uniform frame rate, which should solve the issue.
The Default Resolutions table uses a frame's height and width to assign it an aspect ratio, a scan mode, and a frame rate. You can find the Default Resolutions table in
. It is also used when restoring legacy archives.