There were certain games that worked on Vita and certain games that didn't. A lot of us had digital games on the PSP (ie: the PS1 Crash Bandicoot games or Syphon Filter for PSP) but wouldn't work on the Vita. A couple of days ago, all of the games that weren't working suddenly started working. Some say it was the work of Skynet. Anyway, we were all super happy to finally get our missing games. Today, the ability to download those games has vanished. Those that missed out are screwed unless Sony gives us the ability again.
And now you know.
Alright. Thank you for clearing that up.