Desktop locks up when wireless network drops

Dual boot Vista/Kubuntu 9.10 HP 6715b laptop.

The wireless under Kubuntu frequently drop outs when copying large files across the network. The desktop becomes unresponsive and the system needs to be rebooted.

It's so unreliable that the system is unusable using wireless on Kubuntu. Previous OpenSuse 11.1 (Gnome) installation didn't suffer as much, although drop outs were more frequent than with Vista. However, it managed to reconnect and didn't lose responsiveness.

After a while, it offers the login box to the wireless network, but won't reconnect, even with the correct parameters.

Yup, still happens here too, most often when resuming from hibernate.

Things that seem to help (or at least mean doesn't need a reboot to fix).
Don't use knetworkmanager use 'nm-applet' (killall knetworkmanager;nm-applet &) - only needed once at login
Restart network manager and/or networking (/etc/init.d/networking restart ; /etc/init.d/netwrok-manager restart) - this some times makes nm-applet re-ask for the wireless network password (even though it's a system connection and normally works fine) but just close the window.

You can automate the replacement of knetworkmanager by writing a file .kde/Autostart/nm-applet :
#!/bin/bash
sleep 10
killall /usr/bin/knetworkmanager
nm-applet &

then chmod +x it.

Can't believe this hasn't been fixed as a higher priority - simple sliding the hardware enable/disable switch is enough to trigger it !