D-Link router isn't working correctly.

My D-link wireless router (a DWA-140) has been working very well for about that last 6 or 7 months now; then, out of nowhere, it suddenly seemed to act wierd. Out of the blue, it just disconnected from my usb signal reciever and conneted to a different router from the neighbor's home. Whenever I click on the my router to reconnect, it only connects for about 20 seconds then it starts saying its connecting to 'access point' then it connects to the neighbor's router. I've tried going onto the D-link website (The thing where you log on to adjust router settings0 but i keep getting an error saying 'this destination doesn't exist' and what not. Help much appreciated.