It is ususal that every time you connect to a wireless network location the signature is left in windows which makes it easier to connect it next time.  But sometimes when you connect manually to the same wireless network again it creates another signature. This results in creation of multiple network profile. 

WIndows VIsta allows you to manage networks and merge them into one if you face the similar situation. To find how to do this :

• Open Control panel > Network and sharing center
• Now select one of the networks and look for custimize link. ( It should be on right hand side )
• Once you click on Customize, you will get another window which allows you to make the network as Private and public. Right under that look for Merge or delete network locations.
• Now select the source and destination. Destination should be the network you are currently connected to.
• Select and Merge. Thats it.

Customize and Merge Network locations

Merge other network locations with Source