Not sure whats going on, but at the time of checking your site, it wasnt working. I just get blank outputs on for example this:
http://parrotmouse.ojodigital.net/Luz-r ... t/portada/
I am not sure what your gallery looks like, but it does adapt the layout to a certain degree, yes. I am not sure how you expect the menu to work - What if you have an item "This is a veeeeeeeeeeeery long folder title" - The menu will have to adapt to fill in the width of such an item. That is why the menu is collapsed by default so it doesnt interfere with the images. As for the image, they do resize and adapt to the screen size. This means they display at maximum size if possible, but resize downwards within the minimum margins set in the settings file. Almost all other elements on the screen will adapt also - The audioplayer will align to right, thumbnailscroller and controls will align at bottom, text will display based on image position. As you may understand, we cant take background images into consideration - Thats why all the themes from us have image aligned from a corner and not created for a specific resolution.
You may have had problems with the "startpage" or filemod feature. This is a module that simply loads any custom item you tell it to - It will not resize this item like it does with the normal images in your gallery.