I'd pull power from your router and plug it back in. I'm not a router expert, but it sounds like you have it setup for DHCP, but that for some reason you system is being excluded. If that doesn't work, check out the settings in your router and see if there is an exclusion policy that was maybe set?
You can also try posting over in the wired forum:
I guess I neglected to mention, my laptop worked just fine with this wireless router until a couple weeks ago. It quit after I was offsite one day using a customer's d-link router. I lost the connection from that router and couldn't get back on. Then when I went home I couldn't get on my d-link either.
You may have an AV / policy setting issue.
Some corporate laptop get configured to block connections to "non-secure" access points (like any default setting wireless router)
Some AV \ firewall programs will block network connections to networks on which it detects a "threat"
It could be that when connected to customer's d-link your firewall detected an invasion attempt and blocked the SSID "D-link" so now you can't connect to any router with that name.
You firewall logs should show this or safer, would be to change you home D-link SSID and enable security to keep the neighbors out also.