I reported this upstream. It's bug 2745107 on project libmtp at sourceforge. As I noted, I found the first change that caused problems and (correctly, as it happens) guessed that removing the DEVICE_FLAG_BROKEN_MTPGETOBJPROPLIST_ALL flag for my device would work, and it does.
Presumably the flag's needed for some versions of this device (perhaps firmware versions change this) so it's probably not a suitable general fix. However, for anyone else finding the same problem, this fixes it for me: remove DEVICE_FLAG_BROKEN_MTPGETOBJPROPLIST_ALL from the flags for "Creative", 0x041e, "ZEN", 0x4157. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org