Seeing how people are having issues with SD cards I thought it would be a good idea to approach these problems systematically and more accurately instead of spreading hints all over the forum

This could help the Kobo developers to solve the problems.
1) State brand, model number, type (
SD/SDHC/SDXC) and capacity of your SD card.
2) Provide link(s) to the book(s) that is (are) giving you problems.
3) How do you manage the books on your Kobo Touch? Drag&drop, Kobo Desktop application, Calibre, other ... ?
4) Which firmware version are you using?
5) What type of problem are you having?