N900 Just stops, requires power cycle

Update on my side… I had turned QoS off for a few days and it hasn’t happened since (although the post about once a week is concerning).  But because of issues I"m having streaming video via DLNA I’ve had to turn on QoS - that hasn’t solved my streaming issues (see http://community.wdc.com/t5/WD-Networking-Devices/Optimizing-for-Video-Streaming/m-p/519158) but I’ll keep an eye on whether it causes my WLAN to stop working again.