Exactly what do you mean by "wrong" IP address? Is it an address from your router? If it is then, as B. Diddy said, the router is assigning an IP address to the tablet, and it's the next one available. So if you connect after someone else does, you might get 192.168.1.6. The next time, that other person isn't connected, so you get 192.168.1.5.
If you mean the external address, make sure you're connecting to your router, not someone else's with the same name. (The only way the tablet knows which router it's connecting to is the router's name, the SSID. And there's no preventing a neighbor from using the same SSID as you do. (Routers usually come with the manufacturer's name as the SSID. If you don't change that, your neighbor doesn't, and you both have routers made by the same manufacturer ... you could easily connect to the wrong router.)
If it's something else, spell it out (and put my name into the post, so I'll get notified that you addressed something to me).