iOS works with a 'point' unit, which is similar to the dip values in B4A, and not pixels.
On your device the scale is 2 which means 1024x768 points.
The difference between 1024 and 960 is the height of the different bars (StatusBar, NavigationBar, ToolBar, TabBar)
Have a look at chapter 5 Screen sizes and resolutions in the B4i Beginner's Guide.