I am on my fifth WGT634U, and so far 3 of them have suffered all kinds of random crashes and segfaults. My first case seemed like it was the MADWIFI drivers, as once the card initialiazed, you would experience random "virtual smoke". (kernel panics usually)
This is caused by a BAD DESIGN on the power regulation circuits in the WGT!
The "stock" power transformer that came with my units is a Linear "wall wart" type with an iron core transformer rated at 12vdc & 1200ma. On 3 of these, the open circuit voltage was in excess of 18vdc and the voltage with the WGT connected was over 15v. This is a little "hot" for the small buck regulators on the WGT mainboard. In addition, I was pushing close to half a volt of AC ripple under load!
This seems to get them too hot and after a bit the router becomes unstable. My first-glance analysis is that there is a lack of filter capacitance for both the input and outputs. I will do a more through analysis and post my findings here soon.
Until then the best solution is to run a power adaptor that is actually at 12vdc or lower under load. I have found that a 5vdc adaptor works fine as long as you aren't using USB, and a 7.5vdc is perfect for everything.
So if you are experiencing strange crashes, BEFORE reporting a bug or opening that ticket, PLEASE try a lower-voltage power supply!
If you aren't using USB, the ones for the other Netgear products (5VDC) work great!
Hope this helps!!!