I've only had my PS3 for a week, and I've had "Corrupted data" entries show up in my games list at least 3-4 times. The last couple have been 0 KB, I've had no trouble deleting them, and I've had no issues with stuff I've downloaded. I think it seems to happen when I set the PS3 to turn off after completing downloads (which I've been doing a lot, as I've grabbed all of the PS+ stuff), but I'm not sure all of the cases have been that.
Also, one time, I started up my PS3 after leaving it overnight to download stuff, and a warning telling me it didn't shut down properly came up, which I unfortunately accidentally skipped.
I've seen a bit of discussion online saying this is relatively normal, but man, as someone who knows a fair bit about computers, any sign of data corruption sets off massive "OH SHIT, DO I HAVE A BACKUP?" red flags. That said, this doesn't feel like it's a issue with the drive, because everything has otherwise been working flawlessly.
Should I be concerned? I'm going to back my system up to a USB drive tonight just in case, which seems to be all I can really do to mitigate this.