Since the last official firmware update from SanDisk, the European aircraft have noise curb has 100dB (European legislation obliges).
That causes problems for users using external speackers.
With the little trick next Sansa-fuze.jimdo.com helps you bypass this restriction:
Go into the settings menu
then System Settings -> Factory Settings
Restore factory settings so yes then select the language and region of North America.
Accuracy: this does not change your firmware version.