I installed a theme from my computer (Black sleek) and I have it for v2 Beta Public, but when I apply it just turns my forum white and no tabs, ect.
no images right?try to upload images and style.css from that theme.
Are you sure the theme is fully compatible with SMF 2.*? Also if the tabs/images use your langauge settings it might not have the language you use installed.
If you link to your site, we can take a better look.