Using TweakIt, go to the following registry key:
 HKEY_LOCAL_MACHINE \ Drivers \ Display \ NVDDI:
 Please add the following value to the aforementioned key:
 QVGAmode = DWORD: 0
 Then warm/cold reset the unit.
 You'll see that the screen is now in FVGA mode:

 
 
 
  1. screen shot in FVGA mode
 
By default, the screen size is set to QVGA, hence  QVGAmode = DWORD: 1
For Omnii XT10 How to switch display from QVGA to VGA? click here