If I had to put money on it, I'd say they haven't fixed it.
(I've never used an SD card with mine.)
I've been in to look at the Mini again this week. WHSmith don't have the same half-price accessories offer they had last time, so it's bit less of a good deal if you also want a cover. Also, two of my colleagues bought them last time, while I manfully resisted, and I don't think either of them have used the device at all. (They both have other readers.)