Mate Victor:
first: multimode.ini is in data.zip/ui_android/multimode.ini - no iGO/ui_android/
second: m5 and m6 - this is line for resolutions 1024x768!
for resolution 800x480 is line m3 and m4.

Correct your proposition is:
m3 = 1020..1280,500..800 "800_480"
m4 = 500..800,900..1280, "800_480"

regards wojpen