What country do you set if you create Hard reset?
Do you set UK or USA?
Maybe this is reason why don't work.
have now done all suggested but for some reason the unit will not let me change the speed limits, did before i started messing around .... however i think i can live with it as it is
Maybe something wrong with this Nuvi's Sqlite application and associated files.
Speed Corrections are housed in /.System/SQLite/SpeedCorrections/speed.db
Maybe this file is corrupt.
Try to delete this file.
Also check directory structure.
Check if you have 2 maps of the same area loaded in the Nuvi.
Some roads do not let you change the speed, The road where I live shows + all the time no matter what I do, Other roads I can change.
The difference between stupidity and genius is that genius has its limits.