Typically scene detection works by looking at the time / date code info that is recorded on the tape. If you play the tape back on the camera, with the display settings set to show time / datecodes, has it recorded them correctly?

The other way the scenes get detected is to look for changes in the image composition, but that always seems hit or miss (mostly miss) to me anyway.

Perhaps something happened to the camera to have it forget the date settings, and like that old flashing VCR its sitting waiting for the date and time to be set? Just a thought. Otherwise check the camera instructions to see if you accidentaly switched off the datestamping (I dont know if thats even possible) Either way, I doubt it has anything to do with the way the camera is connected to the card.

Good Luck!