What you may want to do is check settings within the wireless router. There should be some kind of setting where you can change the "channel" (usually 1-11 in a drop down list, going by memory here) that's being used. D-link tends to default to channel 6 as do most other makes, making this the most commonly used channel. It's possible that your Belkin could have had a different default channel setting.
I had this same exact problem and had noticed that there were like 5 other wifi connections around me, so I changed this setting to something other than default and it cleared up.
Post back and let us know if this corrects the issue or not.