After seeing this error popping up a lot while having issues with my internet connection dropping packets left and right I searched CFNetworkErrors.h for what the error code meant (since Google didn’t say much other than it appeared in 10.5.3). The line in question is: kCFErrorHTTPConnectionLost = 302,
So if you get kCFErrorDomainCFNetwork: 302 errors, it’s because the HTTP connection was lost somewhere along the way. As to what causes it can really definitely seem like voodoo.