Any other gadget in the house can connect to the wifi except my samsung galaxy ace. It says "Connecting", then "Disconnected", then "Disabled. Secured with WPA/WPA2 PSK". I've tried the #.#5 something solution and it doesn't make any difference. I've tried connecting with my aunt's wifi and it works just fine.
Can you provide a logcat of the issue?
Assuming you have ADB, connect your Ace to the PC, fire up ADB, and type
adb start-server adb logcat > logcat.txt
The issue is probably because the router is having trouble giving out addresses, but I'm not sure.