How can wireless card change SSID and other settings on router?

I have a new Dell Vostro laptop 1320 that came with an Intel 5100 a/g/n wireless card.  I brought it home and went to set it up on my existing home network, which has a Linksys WRT400N a/g/n router/access point on it.  The Intel setup on the laptop asked for the router ID number that's printed on the bottom of the unit, which I supplied.  (That sounds like a real security issue to me, by the way.  Anyone that's in the house and knows what they are doing could write down that number and then join the network.)  The system went through it's configuration and joined the network on the G range, but it also changed the SSID of the A/N portion to Linksys_**** (I forget exactly what came after Linksys, but it was originally named by me to be something totally different.)  When I connected to the newly named N range, after again supplying the code from the bottom of the router, the SSID of the G portion changed, also to Linksys_****!  This was a real pain.  I needed to connect manually to the router through a wired connection and change the SSID names back so other machines in my house could again access the network.  How could this possibly happen?  The security (was set to WPA2) at some point also vanished, although I'm not sure if that was when I was in the router reconfiguring or it was during the laptop setup.