I did run into this even though I followed everything said here.
Assuming that you did follow this link, here's how I solved the issue :
Long story :
Everything was working fine until I copied the whole project on another PC and imported it into Eclipse. This changes everything, because the API key you obtain is linked to the debug keystore on the machine that you used to generate the API key. Since I was running / debugging the android application on another machine (hence another debug keystore), the API key was invalid. So I had to generate a new API key as described below.
Short story :
If you are using another machine , generate a new API key, by computing the MD5 fingerprint as described here, and then generate the API key here using this MD5 fingerprint.
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