I'm having a great deal of trouble connecting to my roommate's network. My previous network - no problem. The Internet at work when I'm on break - easy. For some strange reason, despite having the correct password and connecting to the router successfully, I only get a Local Area Connection. Something is keeping my computer from recognising the modem, or something that is blocking the actual network identification (as it still lists it as "unidentified network," despite connecting to the router without an issue). I can connect with an ethernet cable, but that doesn't do much for Internetting in my room. I have tried power cycling the network and I've tried my damndest to find where I can set the IP settings manually, but to no avail. Vista's Network and Sharing Center is a funny creature.
I had a similarsituation and found that the security protocol was WPK and set to tkip somehow it let me connect with my security set to AEIS using the same password but would not allow me to browse the internet but did accept a LAN connection I changed to TKIP and it worked fine Maybe nothing but worth a simple check, some guru guy explained it was something to do with the firmware on the router and Vista who knows but it did work for me.