I heard a conversion on TGIF earlier where a user was directed to this post for instructions on how to reset his Pi-Star dashboard password.  The instructions posted here are for changing the pi user password on a standard installation of Raspbian.  These instructions won't work for Pi-Star.  For example, there is no pi user on Pi-Star.  You can get the instructions to work if you change "passwd pi" to "passwd pi-star", and add "mount -t proc proc /proc" to the instructions.  But be aware that only changes the pi-star password used to login at the terminal.  It does not change the pi-star password used on the dashboard. 

My suggestion would be to always back up your Pi-Star configuration -- using the Backup/Restore feature under the Configuration menu.  If you forgot your password, re-image your SD card and start over from your backup file.