I use a ADSL route Speedtouch 413514 and my networkcard is a E-Tech USB WLAN(Ralink2500 I think) and when it happens I go to the Networkmanager and let it scan ,he don't find my router ...he find nothing,because I live in a appartment and normally he find several routers...and the only thing I can do is restart my computer.
Hmm, it looks like ralink drivers are buggy. I'd try ndiswrapper in that case:
* uninstall ralink drivers from package-manager
* install your usb stick's windows drivers using ndsiwrapper: http://en.pardus-wiki.org/Using_Windows_wireless_card_drivers
You should use modprobe -r modulename
command as root to unload your current drivers or just restart the system after uninstalling the drivers from package manager. (lsmod
command lists currently used drivers and that helps you get the modulename in that case)