Different Adobe ID??

Good day all,

I have downloaded quite a few e-books on my iPad, without any problems, until last week. I bought an e-book for my daughter, and suddenly

I get a message stating "The item has previously been downloaded with a different Adobe ID. Please add that account to the device." I'm

relying on my memory for the exact words, so the above may differ slightly.

I only registered one Adobe ID (username and password), where does this second ID / account now suddely come from? And all the other

e-books (some from the same writer or publisher as the latest one) works fine. I use the Bluefire Reader.

Any ideas would be highly appreciated.

Regards.

Paul.