Readers eager for digital books were out of luck at Amazon's Kindle Store for a short period today.
Shoppers could browse the site with their Kindle e-readers. But titles were listed as "currently unavailable."
Amazon didn't immediately reply to requests for comment.
The store resumed normal sales by about 1 p.m. PDT.
Correction 1:39 p.m. PT: An earlier version of this story incorrectly reported that the new digital versions of the Harry Potter series were affected by the outage. Buyers of those titles on the Kindle store are redirected to the Pottermore Web site, which handles those sales.