I'm glad we responded with that quickly. I had to write something quick because I was stuck behind the great firewall and didn't have full access to the internet.
Thinking about this a little more, can you tell me what image you're using, and what version?
We found that with some of the wifi dongles the drivers are not properly available. I can walk you through installation if that's the case. Because we've replaced the hardware once, odds are there's something missing on the software side.
Let me know what version of the image you're using and how you got it setup. We'll figure something out.