I have a wireless access point at home and I can't connect with my laptop which uses Kubuntu 12.04.
My wifi access point is configured to hide the SSID and use WPA2 Personal encryption.
When you scan for a wireless network, do you see your access point?
In any case try playing with some different security settings. Connectivity issues can sometimes be caused by incompatibilities between your wireless card, router, and security settings. In other words, this is not necessarily an Ubuntu issue :)
You might also look at the question linked below for some answers which might help you. Wifi Connectivity problems when using WPA/WPA2 Encryption
Stop hiding the SSID and see if that makes a difference. Here is a link to a site I found with a Google search. It provides more detail on why hiding an SSID is not a good thing to do.
A simple Google search will turn up other sites which offer the same advice. The search will probably also return a number of claims by well-intentioned yet mistaken individuals claiming hiding the SSID tightens security.
They apparently do not know how to use Google so how much trust can you place in what they say? And how is it no one ever wagged a finger at them and told them that "obscurity is not security"
If you want to dig into the documentation you can try starting at the Ubuntu Community Help Wiki's Wireless Networking Central.
The following command will most probably solve the issue: