Linuxluver:It's representative of the level of (in)accuracy of the Galaxy S GPS. Even 15 minutes later it rarely got as close as 10 metres...and usually more like 20 or 30...as the bubble says.
This test isn't exhaustive or definitive.....but it is a good indication of what I have been seeing for several weeks.
I'd be trying different firmware on your phone. My Samsung Captivate (Galaxy S) completes this test perfectly from inside my house while down a story from the roof. I've also been using it with Navigon Mobile and it works freaking awesomely.