It is all a matter of skinning, there is no magic switch for compatibility with screen resolutions or browsers.
Most of the included skins work well at 1024x768 or larger. Some skins look better than others in IE 6.
During the skin design process one should test in all the screen resolutions and browsers that are important to them.
Though the actual design should be done using Firefox and then when testing in IE if there are problems they can usually be solved by overriding CSS in the IESpecific.css files. Though often it can be a time consuming pain in the arse to get things tweaked just right in IE 6.