Hey, I got the same router, and I'm just gonna throw it out there, that firmware your using, 1.8, is only beta and isn't even available on D-link's website anymore because of its instability.. I tried it, and the router started to crap up right as it updated (crashes, disconnects, etc..). That might be the source of all your problems. I downgraded back to 1.7, and everything went smooth and flawless. Might wanna try it, but save a copy of your gateway settings before you do, just in case thats not the problem....

Borgslayer