I think you are correct about antenna placement being the issue of bad performance.
Nokia should have done a better job of designing a product that was to compete with stand alone GPS units.
I did understand when buying that installed software was for location only. It takes some time to initiate but it eventually does that.
However due to the poor performance of the receiver I would not buy voice and direction software pckage from them.

In my opinion they rushed this product out as a convergence device when it was not ready to be one.

If you need GPS for travel buy stand alone product.
If you want a small internet tablet then N810 works well.