I have had the DGL-4500 for about a month now, and not a day goes by that it doesn't reboot itself. In fact most days it reboots multiple times per day. I have Comcast cable using a Linksys cable modem and I can confirm that on each reboot of the DGL-4500...the cable modem is still passing traffic as a connected laptop (I placed a switch between the router and modem as a test) still remains online. The firmware version is 1.23NA. Nothing in the logs tell me what may be going on. I have turned off just about everything I can that I would suspect puts the router through additional processing (workload) and nothing works. Disabling the dynamic defrag seem to help...though this may simply be my perception since I want something to work.
I work from my home during the day and am hard-wired to the router, but it still resets. It seems to be worse during VPN sessions, VIOP calls, or GoToMeeting sessions...I suspect heavy traffic usage. Another heavy traffic example...we cannot watch a full length movie on Netflix wether on a PC (hard-wired or wireless) or a wirelessly connected Xbox without it rebooting. If my family is home and connected via wireless, it reboots at least once an hour (often more), wether I am using any of the hard-wired PC's or not.
I purchased the router from Newegg and the user ratings warned of such issues with the router. I have also found other sites with user complaints about the same issue. When is D-Link going to provide us with a fix to this issue. My previous DGL-4300 ran fine for more than 3 years under the exact same conditions without issue, until lightning took it out. The reboot issue is well documented and a firmware update is obvious, but why haven't we seen one?
A rebooting router is utterly worthless to me and I need an answer or time frame. Otherwise, it is time to throw the router away and make another purchase, presumably not D-Link.