My parents just installed a new modem/router after having switched ISP's. It installed fine, and (almost) everything works. My dad's desktop is connected with a wire and he has complete access to internet. My phone connects wirelessly and has normal service as well.
My mom's notebook however simply fails to make a connection as long as it's running on the battery. However, as soon as I plug the notebook's adapter in the wall socket and try to make a connection, it works. I checked the power management options and there's nothing there that can cause it. Besides, if I recreate the set-up (N-standard wireless network and notebook running on battery) either at my own network or the office, it just works. Connection attempts don't even show up in the modem's log. These attempts do show up in Windows' log, stating the security key is invalid. I'm 100% sure it is; if so, it wouldn't when plugged in as well.
Dell Inspiron 1545, Windows Vista 32bit