Ok, tried running it in python shell and got this error:
>>> mxd=arcpy.mapping.MapDocument("I:\GIS_Workspace\Ventura_Area\Danny\SAPTList.mxd")
arcpy.RefreshActiveView();arcpy.RefreshTOC()
arcpy.mapping.ExportToPDF (mxd,"I:\GIS_Workspace\Ventura_Area\Danny\SAPT_MAP.pdf")
Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
mxd=arcpy.mapping.MapDocument("I:\GIS_Workspace\Ventura_Area\Danny\SAPTList.mxd")
NameError: name 'arcpy' is not defined>>>
Again, this SAME script run beautifully in ArcGIS.