Mpeg2 file aspect ratio is incorrect all of a sudden

I have been using Media Encoder for years to encode mpeg2 720x480 (square and non-square) footage in.  All of a sudden it doesnt correctly identify the aspect ratio.  It says the source is 540x480.  I have tried to Interpret footage to change it, but it doesnt accept the new change.  It's cropping the video because it thinks its 540 instead of 720 so I'm losing about a third of the field.  Is this a new bug that it doesnt understand mpeg2 video anymore?  I'll add that these are.mpg extensions as well.