After updating to Blender 2.68 Driver Scripts are no longer automatically excecuted When loading a .blend file the console window shows error messages like:

skipping driver 'x1*(1-x2)', automatic scripts are disabled
skipping driver 'x1*(1-x2*x3)', automatic scripts are disabled
skipping driver 'x1*(1-x2)', automatic scripts are disabled
skipping driver 'x1*(1-x2*x3)', automatic scripts are disabled


In the file browser the option Trusted Source can be set but isn't remembered when using File: Open Recent



Can the new security features switched off?
You can turn this setting off in the user preferences by unchecking Auto Run Python Scripts:



See the wiki for more information.