In reply to the last;
I have selected the 'Mass Storage Mode Support' option to 'On' and, as advised reconnected my device etc...now several times. Yet, the same problem exists - I (we) come round in full circle to:
'This BlackBerry® device requires mass storage mode to sync your music files. Turn it on in your device options, reconnect your device and try again to sync with your media card.'
Like I said, I have done so...but to no avail!