My Supernote's IP address keeps changing — do I have to reconnect every time?

Usually no. The app remembers the last address and tries it directly on startup; if it's changed, it scans your network to find the tablet automatically. Addresses can change because your router hands out a new one (DHCP), and the tablet drops Wi-Fi in deep sleep — so if it won't connect, wake the Supernote and re-open the Browse & Access screen, and the app will pick up the new address.