Windows Vista Wi-fi, wierd behavior

[Bovenation]

The only way for me to connect to the internet in my house is through a wifi network that my entire family shares. Every so often, I have this problem, fix it, and forget how I did it for when it happens again. The problem is:

 

There are 2 main networks around my house. One is the one that my family owns. The other is our neighbor's unsecured network, which gets a usually low signal and is a back-up for when our internet is being worked on, fixed, etc.(Don't worry, I don't make it a habit to use the neighbor's network, it's only for information gathering in emergency situations). If my computer somehow gets signed off our internet, it will switch over to the neighbor's internet automatically. The only thing is, once it switches to the neighbor's, I can't get it to reconnect to ours again.

 

I am using the D-Link DWA-125 wireless adapter. If I type the network security key into the D-Link network utility, there will be no active internet connection for about half a minute, and at that point it will switch over to our neighbor's. If I try to use Vista's default wireless connection thingy, it will say after less than a second of trying to connect that the "Connection was cancelled" and that this "Might be due to a timeout or user action." This makes no sense, because I obviously didn't screw around with it and there hasn't been any timeouts with the unsecured network, so it must have something against me using security keys, idk. Look, if anyone knows how to fix this, please let me know asap, it's driving me crazy.