Well I just mutli tabbed in the India store and had the same experience as mentioned by a couple of other posters: Internal Error. See below for a pic of the error.
Any yet the book went into my library as normal. I haven't received a receipt either.
(And no, I couldn't re-use the code after the purchase went through.)
Heavens above ..... don't tell me that Kobo might be trying to fix this wonderful initiative that they've been trialling!!!