Although this may not be related to your issue, here's what was going on with mine.
First some background. Just got a new LG Blu-Ray BD570, so on the advice of one my co-workers, I picked up a DIR-655 to go with it. Was previously using a Linksys WRT54GS, very few issues with that. I got the 655 for the Wireless-N support that the player supported.
Yesterday after work, I got both set up on my network. The dlink auto config tool did not work, so I had to manually configure the router. That came down to setting up my Cable IP's DNS IP's, then recycling the cable modem. After that I was off and running. Watched a Netflix movie last night, was getting 130Mbps with it. No time outs while streaming. At the same time, my wireless G from my laptop was still pulling 54Mbps. I was pretty happy.
Today I get home from work, and my wife's very upset. Throughout the day, she had loss of internet throughout the day, cycled everything once with no results. Along with the above setup with my Wireless-N blu-ray, I have with 2 Lan PCs (both at 1000T), and we're also on Vonage. We're also beta-testing one of their new boxes (yup a lot to throw at this new setup).
So after doing some debugging, here's what I found gave me some great improvement and solved my loss of wireless:
1.) First when I got everything set up, I turned on my logging, and got it set up so it e-mailed me the logs. That was incredibly helpful.
2.) Going thru the logs, I saw some constant IP getting resolved. Googling it, it turned out that it was from the SecureSpot setup being on. I shut that off and reset the router. No more constant pinging. My phone quality was slightly better doing this.
3.) After getting new logs, looking thru them, I noticed that my wireless was constantly dropping, even if I ddn't have any wireless devices turned on. I also noticed when I was on the phone, every time it dropped, my phone signal briefly lost signal (Vonage device uses one of the LAN ports). On a couple of occasions, it totally cut out. This would also go with that my wife reported while playing one of her online games (Runes of Magic), she lost internet connectivity for a few seconds on and off during the day.
4.) Digging thru more of the wireless settings, I changed the following: 1.) Turned off WISH, 2.) DISABLED the auto channel scan in the wireless setup, 3.) Set a specific wireless channel (right now on channel 1), and turned down my channel with to 20Mhz (I read somewhere on some other side that doing this seemed to give better performance on some wireless devices, while could affect others negatively).
5.) After making the above changes, I reset the router. I went back and called my friend. Chatted for about 45 minutes straight, no dropage, no cut-out of voice, everything was back to normal from when it ran thru my Linksys. I also streamed Demolition Man thru the Blu-ray, no pausing, and still at 130Mbps. Benchmark thru my ISP shows 8.46Mbps download, 1.05 up, 22ms ping time. About what it has been before my upgrade.
Seemed like getting off auto-channel was the culprit to my wireless being reset all the time. Pretty stable now for the last 2 hours.
Oh yea - I have not upgraded the firmware - running Hardware Version A4, Firmware 1.32NA. If the wheel ain't broke, don't fix it.
Hope that helps. Good luck!