Moving PSN items to a different memory stick.

I only have a limited amount of space on my PSP's memory stick, so I thought I'd store stuff I wasn't using on my computer to make room. I just moved Tomb Raider III back to the memory stick again and when I try to play it I'm told the copyright information is invalid.

I moved all of the TRIII files from GAME and SAVEDATA to my computer and onto a different memory stick. Is there something else I needed to copy?

Nevermind, I got it. I had to copy everything from the LICENSE folder too. Seems way obvious now.