Well, to check the two obvious things:
1) Have you run a Verify (or repair) on the drive via Disk Utility, to make sure the directory is okay? If not, do.
2) Is this an Apple-stock SSD, or a 3rd party one? If the latter, it's possible it's some kind of firmware weirdness, so you should check to make sure that the firmware on the SSD is up to date.