I have an iPod 5, registered with Shaw Go Wifi. I can connect to the Shaw networks when I'm near a hot spot, and it prompted me the first time to login. But since then, it never automatically connects. I have to go into Settings - Wi-Fi and choose Shaw Open from the list in order to connect. It doesn't matter which hotspot - it's happened at every single one I've been to.
At first I thought that was the way it worked, but a friend showed me how hers connected without her having to tell it to. I don't have "Ask to Join Networks" on and I can't see any reason on my end why it wouldn't auto connect like it does on my home network. My MAC address is listed in my account, and it seems like everything should work.