It says it only works on pre-installed (V) models.
Also, compression depends on the material - 4x would be typical only for easily compressed stuff.
Other options...
http://www.richskills.com/support/us...uard_help.html Remora USB Fileguard - compression and encryption for any USB drive.
Or equip your USB drive with
http://portableapps.com/ - adding 7-Zip portable to the base/lite edition, so you carry a powerful compression utility.
__________________
Mary had a little lamb,
Her father shot it dead
Now Mary takes her lamb to school,
Between two crusts of bread