Lightroom :: Original Date Showing Is Wrong

I seem to have a big (and very weird) problem with dates in Lightroom. This relates - for the moment at least - to images dating back ten years, to when I had my first digital camera, a Nikon D100.
 
My belief is that the photo in question, one of many, was taken at around 2pm on the afternoon of 17th April 2004. Note the following from the image (EXIF data):
 
- The "date/time original" shows 17/04/2002 13:58:48
- The "date/time digitized" shows 17/04/2004 23:15:29
- The "date/time" shows 17/04/2004 23:24:17
 
The same image in Windows explorer (see second image) shows:
> Date 17/04/2004 23:15
> Date Taken 17/04/2004 23:15
> Date Imported 17/04/2004 22:24
 
Given the subject matter of the image, it is 100% certain this image was in fact taken in April 2004.
 
How can it be, then, that the "original" shows a date two years earlier? Why would Lightroom use this field (the ONLY one showing 2002 when every other shows 2004)? And why does Explorer correctly show the date but Lightroom does not - surely if anything one might expect the opposite?
 
This is urgently needed to be resolved as I am making a photo book for my wife's 40th and, as it turns out, I am putting all the photos in all the wrong years!