** When clicking on "Reply", I twice had an error flag. My message, above, remained in an edit pane, although I could see it 'greyed out' and labelled with my ID & "Waiting on Activation". A third attempt, when the this message had been accepted at 22m, proved successful - but the timer re-started. **
Following the partitioning & formatting to 64 GB on the flash drive, on Win XP, I then shovelled a some 16 files = 5 GB on to it, still in the USB 2.0 slot. After transferring and emptying on to Ubuntu, I again plugged it into the same slot. The usual XP clunk sound, followed by automatic opening of window for this media AND a message-pane indicating suitability for USB 3.0.
Then I removed this flashy drive from its USB 2.0 slot and popped it into a 3.0, where I formally DID NOT register. Now, all is hunky-dory.
Save, that is, it has incorrect sector-size.
--> Can flash drive remain as NTFS, but change to 'correct' sector-size = 16 KB?
Without the nitty-gritty on matters flash drives, it is a difficult playing field. Offering a link or search suggestion would be appreciated.