Kubuntu 10.10, Calibre 0.7.59 with 0.8 features enabled:
When downloading covers for multiple books Calibre failed to download the cover for a number of them. The message text read:
Code:
Finished downloading metadata for 182 book(s). Proceed with updating the metadata in your library?
Could not download metadata and/or covers for 0 of the books. Click "Show Details" to see which books.
In reality, it was 151 books that were listed under "Show Details", not 0.