Hello mes amis
I recently acquired a Vox and although it is a little bulkier than I was expecting, and something of a fingerprint magnet to boot, I'm pretty happy with it

However, I have run into one rather peculiar issue. When side-loading books from a memory card, I have very mixed results with cover images. Sometimes the Vox fails to see the cover image at all for no apparent reason - (and yes, I know there are cover images present because I open most of my side-loaded titles in the Calibre application to tidy up the metadata) - and just as frequently, it sees the cover image and displays it on the virtual shelf, but then fails to display it when you actually open the book, presenting a blank rectangle instead on the cover page. Anyone got any idea what's going on? Is there some size limit to cover images or other criteria I'm missing here?
A related is the Vox's handling of PDFs - some open happily, others appear to be completely invisible to the system and so cannot be imported.
Any pointers/ info gratefully received!