I presume it takes them from the top down until it finds one that resolves. And I can testify that 8.8.8.8 is up as well as Open DNS.
At this late hour it's getting out of my league. I can't tell you if it's a config issue or a bug. I see you just registered today, don't give up on the forum, there are really great guys here. If nothing else my posts have kept this thread nearer the top of the list.