[update: fixed by formatting sdcard, reinstalling NMT, and iterating over the 'remove device' option until the device is really gone (about 5 times), then add the device as normal and carry on with a working NMT]
For Mac users, Nokia Multimedia Transfer has provided an iPhoto image capture plugin, allowing the N95 (and other devices) to operate as a digital camera when connect to the mac. ie: iPhoto pops up, shows a large digital camera icon and lets you copy or move images from your nokia to iphoto (exactly the functionality provided when any digicam is plugged in).
well - my nok no longer claims to have any images available to be transfered. i imagine they are flagged as 'new' by the old camera app (the archive bit is set, assuming the nokia is using the [antiquated] FAT filesystem) and flagged as 'old' (archive bit unset) by iPhoto if the image is copied over (moving the image, obviously, doesn't need to touch the flag).
my guess is that the new camera app, with all its other bugs, is likely failing to set the archive bit. either that, or there is an issue with the gallery app? i don't know whether NMT relies on the filesystem or a built-in app (filesystem would be smarter) but either way: IT'S BROKE.
transferring images now requires manually sending them to the mac, then deleting from the phone. sad.