I've been playing GTA V for 2 days now and I've restarted my Xbox 3 times without any data lost on my USB 16GB flashdrive.
And now I unplugged my Xbox-360 because I was going to move the TV and stuff so I could play GTA V more comfortable. And When I turned my Xbox on and GTA-v it started from 0%, I've done the game > load game things but my data is lost, I checked my system and the install files was still there on my USB stick. But not the quicksave. I quick saved 3 times before I unplugged the Xbox from the 220V wall outlet. And now I can't find the location where I saved everything.