Mac Air 11 wi-fi won't work in europe

I purchased a Mac Air 11 last October in the US, v. 10.7.5. I'm now in Italy and the Mac won't connect with any locally available wi-fi's. (I'm connecting right now using a Vodaphone USB dongle I bought here. It's limited to 5 gig though, so I need to be able to connect with regular wi-fi to be able to use Skype or Facetime back to my family). I keep getting the "connection timed out" message. I've googled this question and seen a lot of confusing and conflicting information. Some people say it's a matter of tweaking settings (though I've tweaked everything I can find), some say that the US-purchased Mac flatly will not work in Europe (something about different channels).

Can someone say definitely that the Mac won't connect here (kind of bites if that's the case)? Or give me a clear way or work-around to solve this problem?

Thanks,

Case