Paul make sure you have only the update on your card.
You can use either the long name file or the 6.180 file. But only one or the other.
1) Power on your unit
2) Restore Factory defaults
3) power off the unit
4) put in the sd card
5) power on the unit
6) wait until the update is done (can take a bit for the 26 mb file)
7) restore factory defaults (again)
remove card
Chuck