GPS on my iPhone

There are a lot of discussions going on about the GPS accuracy on the iPhone. So I started a short test. I tried to get my home position every day and make a screen shot of it - it became 11 days because the error repeats itself on certain days. And I say now that it is not the iPhone (or maybe partly) but that it are those satellites that somehow send wrong signals, because every monday I am here, on every tuesday I am there, etc. So there's a pattern in the positions I am at through the week, although I always was at my house when I took the following screen shots.

I wrote the date in the upper right corner, you can see the time at the top, and put a circle around the spot where my house is. The blue dot marks the GPS spot.







So ... either one of these blue dots should be exactly at my house and the iPhone is very wrong, or all these blue positions are wrong and the satellites do something weird or are too far away from this city.

Update August 2010: since all iPhone3G updates and now my iPhone4, GPS works fine again.