There are two bugs in the 0.52 that this release fix
- The ataidle tools is not used when the ATA parameter are to default (this tools can create some problems)
- Fix the size of USB drive.

For the files:

If you had installed FreeNAS on hard drive/CF/USB, you can use the system/firmware for upgrade it (by using the .img file).

Olivier Cochard
FreeNAS main developer
Skype: callto://ocochard