Whether a skin has the aero frame or not depends on how the skinner designed the skin, and if you have Vista/Win 7. If you're using a skin where aero is enabled in a skin you can override it by running MM in "Compatibility mode: Windows XP".

In MM 4 on my system(Windows 7 x64) the title bar is transparent and ruins the look of most skins(MM3 is fine). Screenshots(on line) of the skins do not show this. Is this typical or am I missing a setting or something?
Hope someone can help :)