Atheros AR5BXB63 won't work with madwifi nor ndiswrapper

I have an Atheros AR5BXB63 which I still can’t get to work with madwifi.
Anyway, so far it has been working with ndiswrapper but every now and
then, when I switch of the laptop it will not connect anywhere. When I
try to connect to my wlan router I get the following:

<info> Activation (wlan0) starting connection ‘System Olympus (wlan0)’
<info> (wlan0): device state change: 3 → 4
<info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled…
<info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started…
<info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled…
<info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
<info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting…
<info> (wlan0): device state change: 4 → 5
<info> Activation (wlan0/wireless): access point ‘System Olympus
(wlan0)’ has security, but secrets are required.
<info> (wlan0): device state change: 5 → 6
<info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
<WARN> get_secrets_cb(): Couldn’t get connection secrets:
nm-settings.c.307 - Missing implementation for
ConnectionSettings::get_secrets…
<info> (wlan0): device state change: 6 → 9
<info> Activation (wlan0) failed for access point (Olympus)
<info> Marking connection ‘System Olympus (wlan0)’ invalid.
<info> Activation (wlan0) failed.
<info> (wlan0): device state change: 9 → 3
<info> (wlan0): deactivating device.

It won’t connect no matter how many times I try to. What normally works
is to do:

modprobe -r ndiswrapper ; modprobe ndiswrapper

but I don’t know if that is the better way to solve this problem
(actually is an inconvenient since I have to do su to get to run that
command).

Can anyone help me with this?

Thank you!

Fede