Complaint: accuracy of compass in 3GS

[SWISSHAT]

I work in a "normal" office surrounded by lots of PCs and lights and overhead aircon ductings.
We experimented with 3 new 3GS today, the compass'es pointed at three different directions in one instance. And when we place the 3 iphones side by side, sometimes they are in synch and sometimes they are not.

So my question is: how much do you trust the compass?
Is this only an inside-building behaviour?
Outside the building the orientation seems ok.

 

[ThatsMeRight]

In such a room with a lot of magnetic fields that can happen.

 

[B737]

im in a field where i can check the accuracy of our compass to 'real compasses' multiple times per day/week (not that i do) but i occasionally do look.

The compasses i check it against are either on an airplane, or on a boat. typically what i find is that its 25-40 degrees off. usually towards 25. I recall a time when i first got it where it was as bad as 45-90 degrees off.