Configuration changes on the PacketShaper are automatically saved once administered through the CLI or web browser interface.

After reboot, though, sometimes classes and configuration changes are lost.

Check that there is adequate flash memory available to allow updates to the file, 9.256/cfg/config.ldi.  There may be extraneous files using up flash memory space. 

The amount of available flash space can be checked with the version command in the CLI. In the browser interface, you can use the File Browser to check flash space, view file lists, and delete files. See Use the File Browser in PacketGuide.