I just installed the Sentence theme. I already have content but when I go to my site the front page is absolutely blank (not even any code in the source!). If I change themes, the pages show up correctly. At first I thought the theme might not work with WP 3.4 so I downgraded to ver 3.3.2 but it still showed up blank (just curious, does it work with ver 3.4?).
I installed the zipped file via the WP web interface. And all the customization pages are showing up in the WP admin pages.
Edited to add: all the permissions are set at 755 and still nothing showing up.