When I suspend with my WLAN card still on, the dhcpcd may crash when resuming or a while after resuming. In that case, the PID file still lingers in the /var/run directory. When trying to reconnect, the dhcpcd won't start up. In Qtopia, you see nothing (as usual) except that the network connection applet stops the connection attempt much earlier.
I've modified my /etc/pcmcia/network script to work around the problem: before trying to use dhcpcd, it checks for a stale PID file (for the current interface), tries to kill any left-over process and removes the PID file. These are the particular lines I've added:
if [ -f /var/run/dhcpcd-$DEVICE.pid ]; then
kill `cat /var/run/dhcpcd-$DEVICE.pid` 2>/dev/null
rm /var/run/dhcpcd-$DEVICE.pid
fi
I've attached the modified script (with .txt extension, because the forum didn't accept it otherwise).