I'm sorry for the lack of detail in this.

The other day I forgot to pay my phone bill, resulting in texts, calls, everything, not working, which seemingly completely irrelevant. Then, whilst waiting for them to reconnect me after having sorted out my phone bill, my N9 asked to connect to my wifi, Ithought why not? Surely crappy temperamental internet beats no internet.

And it worked perfectly.

Once 3g resumed working and I could send messages again, the wifi went back to being rubbish.going offline doesn't have the same effect, and for the life of me, Ican't figure out what made it start working when I was disconnected.

Beginning conjecture, enter conspiracy theory:
What if Nokia crippled wifi to compel N9 users to only use 3g?
IKnow with my N900 Ibarely used 3g, but now, I'm an exclusive 3g-er..

I just realised that removing the Sim should have some kind of effect, will play around with it, but don't hold your breath, the protective rubber case is a biatch!