Remember to look at the description when purchasing USB Drives. The Sandisk/M-Systems joint venture creating the U3 Smart Drive (2nd photo) has the U3 Launchpad executable file installed, which cannot be deleted (1st photo, footnote #1). The MFD can see the executable file, will ignore any/all updates by skipping the updates and booting the MFD into flight mode.
As USB thumb drives are getting difficult to find, an alternative is to use the 2GB MicroSD Cards with a USB 2.0 Adapter Micro SD SDHC Memory Card Reader/Writer Flash Drive.
NOTE: if the USB Adapter has additional slots, the MFD will skip all updates. Avidyne has not tested the USB 3.X Adapters at this time.