Visited my local Atlanta CVS earlier this evening. The manager kindly asked that I scratch to reveal the pin before she rang them up. She said she had 14, yes FOURTEEN, in a row, that were all missing some of the digits earlier in the day. Luckily she caught them all before anyone bought them, but yes, 14 vanilla reload cards missing digits.
I asked if she could tell that they had been tampered with, and she said they definitely had NOT been tampered with. No evidence of any tampering she told me, implying it had to be some sort of manufacturing error.