backup configuration MN-500

Hello

I have an MN-500
Runtime code version: V1.11.017
Boot code version: V1.06

I've backed up the config with all the mac addresses, client filters, time
zone, daylight savings etc etc.

Lately I've had to reset the router a few times due to modem issues with my
ISP.
What's happening is through either a soft or a hard reset, the configuration
disappears.

So I thought, ok, I'll backup the config and next time I need to reset, I'll
just restore the config.bin file.

The config.bin file (and I've tried this several times) seems to contain no
settings and the router stills needs to have all the mac addresses etc
re-entered manually.

Am I doing something wrong? or is this not the purpose of the backup &
restore?

Help?

Thanks

Jim