Change android device physical resolution

I have downloaded an app that, when it starts, check the device resolution and displays a message indicating that my resolution should be at least be 800x600. I have changed my screen density using the LCD Resolution app in order to have a fake 800x600 resolution (it worked well). Problem is that the app still disaplys the error message and displays my resolution has if it hadn't change so I guess it is based on the physical resolution of the device. Is there a way to fake the physical resolution so that I can run the app?