I guess you missed mentioning that you had plugged in the Sandisk key in the meantime (i.e. after system start-up and before launching Gallery or Prospector)? Which would mean hotplug of USB keys is not properly detected, correct?
OK, we tested:
1- hotplug of USB key does not work either with Gallery or Prospector.
2- even with USB key connected before booting up, Prospector cannot find files, Gallery does work. Issue with Prospector might be due to physical path translation patch by us, or might be due to original implementation of the app already.
So both hotplug and Prospector are to be checked and fixed.