Useless? Hardly. It fixes the freezing issues we were getting from checking mail in-game on the XMB Menu.
That happened far too often with me in SCIV, so I'm glad we finally got an update which fixed that nonsense. As for the corrupted data issue though..I can't say I've ever experienced that before, actually. I always have a game in my PS3.
All I can say is..it sucks that it had to happen to you, but let's hope that it turns out to be just a really rare case and won't happen to many other people.