Hello, I thought I would add my piece to this in case someone finds it useful.
In my collection only the Photo Gallery cards are affected by this mistake - just like reinair's Anfernee Hardaway card.
I've currently got 14 Photo Gallery cards (including duplicates) and 5 of them are affected by this mistake so I would guess from my limited sample size it was quite common.
#185 Gary Payton
Zoom-in:
#186 Mookie Blaylock:
Zoom-in:
#187 Charles Barkley:
Zoom-in:
#188 Grant Hill:
Zoom-in:
#192 Karl Malone:
Zoom-in:
As to what could caused this I don't know!
It kind of reminds me of when I was a kid using a PC for my homework in the late 90s. I thought I was being clever using an attractive, fancy font but then when the teacher would open up my work and they didn't have the same font on their system it would get replaced with wingdings!
Edit: My image links broke so I went back through this old post to fix them