[Tara Ka'at]

I recently got a new laptop and installed Calibre again (I had it on my old laptop). I decided to make a brand new Calibre library, so I did not import my old library, instead starting from scratch adding books from various places (Gutenberg and small non-Amazon publishers) and fanfics.
If a book has a cover, or if I add a cover to a fanfic, then Calibre just opens the cover, it doesn't open the book (I've tried changing/converting formats and it's the same behavior for all formats) - there is no small black arrow on the sides to advance pages.
Some books from Gutenberg don't have covers and they open just fine and I'm able to read them. And fanfics without covers open just fine. So I know Calibre is working on my laptop.
Oh, and the Calibre Quick Start Guide also will not open as a book, it's simply a static picture of the cover.
Any and all help is appreciated.