HI, I´ve got a question, I don´t know if I maded something wrong.

I stay developing a game for WIZ, and in near future I want port to Iphone. Today making some probes when compile for Iphone in 480x320, the game don´t make the same behavior than I compile in mode 320x480[this resolution works equal than WIZ, but I need 420x320].
Another trouble is what, in Landscape Mode on Iphone the background shows like ampliated in horizontal, don´t conserve the real proportion of the image, this background are 2 png with 1800px in horizontal, and 220 px in vertical.
Thanks for your help.
Best Regards.
Iván J.
Note:I deleted the command SETCREEN 320,240,true