Thanks for all that - I have only just come back in and I need to supply you with an updated version to give some debug.
A question for you. The dmesg indicates that you have both sda1 and sda2 on the usb, but its saying there are no partitions defined . Are sd1 and sda2 actually formatted correctly???
Dmesg .....
<4>[ 16.684000] UDF-fs: warning (device sda1): udf_fill_super: No partition found (2)
<4>[ 16.854000] UDF-fs: warning (device sda1): udf_fill_super: No partition found (2)
<4>[ 18.466000] UDF-fs: warning (device sda2): udf_fill_super: No partition found (2)
<4>[ 18.652000] UDF-fs: warning (device sda2): udf_fill_super: No partition found (2)