In the past few weeks, I've been getting a lot of "400 Bad Request" errors when trying to download ACSM files from the Kobo store.
(The URL for Adobe DRM content server is
https://acs4.kobo.com/fulfillment/URLLink.acsm)
It usually works after waiting several minutes, but is annoying.
Has anyone else noticed this? Do you know if Kobo are aware of the problem?