This is a pretty decent firewall router(so I've heard), but I can't configure it. You have to do that online. Here's the web address, reply if you can get in it or not: http://192.168.0.1 I can't get in it, but then again Adelphia(my ISP) is having major bandwith issues and I can't even get to google.com. Or linkinpark.com. Luckily I can still come here.
We can't get into your router, that is a local ip address, and won't respond for anyone other than you. You need to crack the manual open, and look at its logs when you find your blocked form using something. Maybe the answer will be here, but also try this other forum as it only deals with D-Link network hardware. http://www.broadbandreports.com/forum/dlink