Try single mode G or N or mixed G and N Under Setup/Wireless/Manual.
Any cordless house phones?
Any other WiFi routers in the area? Link> Use
InSSIDer to find out. How many?
You can change DNS server IP addresses under Setup/Internet/Manual.
You can also do this as well: Turn on DNS Relay under Setup/Networking. Link>
Finding Faster DNS Addresses using Name BenchI would suggest that you try a new ISP Modem with this router as well. Most of the problems seen with any router is mainly ISP services or mis-configuration or LAN cable related. These routers are rock solid and work well when the previous conditions have been correctly addressed.
You might take your router to a friends, family or neighbors place to test to see if the problem follows. If your not wanting to RMA or wait while the router is at RMA, why not go to a place like best buy, frys or some place that has a 30 day return refund policy and get you either a same model router or something different and test out for 30 days. This would give you time to return the 655 to RMA if you can deem it to be the problem. Other 6 series routers to test would be DIR-636L, 645 or 657. The DIR-826L is a nice handy little router as well. I have tested all these models and others and do work well.
Maybe someone from the forums can review your router settings with you using Link>
teamviewer if your interested. Its safe and secure. However seems that D-Link aready has so I'm not sure what else we could do. I feel this could probably be an issue between the ISP modem and router.
@JiN
The M-Router log entires have been seen on my 655 as well. Started with v2.07 and remains in v2.10. Not sure why however I've timed the event to 10-15 minutes then those log entries stop until the next reboot. Doesn't seem to effect anything that I can tell and once the time has passed, all network LED activity returns to normal and router work fine.