Why all themes have problem with 768x1024 resolution in chrome

hello to everyone.

i searched in forum for my problem, but nothing found.
my problem is that why all themes have problem with 768x1024 resolution in chrome, and it's just in chrome, in firefox everything looks grate, but in chrome everything changed and looks messy. the slider has disappear, secondarymenu and mainmenu and logo change itselves and everything gonna really messy!
checked only in desktop Computers ( PC ).


take look at this picture please, it describe everything:

http://uploadtak.com/images/e586_31231251251231231231.png

what is the problem ?
i already checked css and some codes, but nothing found, changed some codes but nothing happened. and for my resolution, width of everything increase in zoom out. like forums width.

hope explained clear for better understand to resolve this problem.
<sorry for my bad english too :P>