Just as a heads up for folks. Recently I updated from shipping firmware in the hope of fixing a wireless issue where the wireless would just drop out, even though all indications were that it was still connected.
So I updated to the latest 311 but that made things much worse, not with the wireless but with a very strange NAT issue. I have a static IP and I static NAT forward a bunch of ports through to my server. Essentially when you select to forward protocol 47 through for PPTP-GRE support it totally loses it and screws up my static IP. I assume this is because of some new app layer gateway support that they added and in true D-Link style stuffed up other things that previously worked fine (induced regressions)...
Ive also found that any attempt to configure the IPv6 support can also screw up the router, forcing a reset of the config and the connection to the internet. It appears that you cannot completely disable the IPv6 support either unfortunately.
If you have any sort of static IP config like I have I would recommend staying with shipping firmware and avoiding the buggy later ones as you cannot go back to what you had.
Im probably gonna go buy something else now as I need this to work correctly. Im not confident in D-Link's quality anymore.