Are the files saved as SBMax templates? Sometimes people offer 'QuickPages' which are actually transparent .png images. You can still use them in SBMax but you have to bring them in as an image. With the QPs you can't move the elements around - what you see is what you get. And if the file is a SBMax template - is it saved with your other templates in the template folder? C > Program Files > SBMax > Templates is where you'll find it.
Hope that helps - if not come back and hopefully someone else can help cause I'd be stumped at that point!