Yup, DRM is such a pain.
I confess to only ever using ebooks from dubious sources in the past, as I'm still in the habit of buying paperbacks of newer stuff. That said, for the first time ever, I bought an ebook from Waterstones for my 650 the other day. 2 days later, "This book is protected by DRM" appeared. I re-copied it over and it's not happened since but the experience really does not endear me towards DRM'd material. Luckily, I noticed it just before leaving for work so it was quickly resolved. If it happens again I'll try the soft reset method.