What you have both brought up here is more "fuel for the fire" for the case of GPS.
As a background, here are the GENERAL categories:
CAT I---MINIMUM OF 200 FT DECISION HEIGHT
CAT II--MINIMUM OF 100 FT DECISION HEIGHT
CAT III--NOW, WE ARE INTO RVR (RUNWAY VISIUAL RANGE)
CAT IIIA---RVR 700FT
CAT IIIB--RVR 100FT
As OPNL correctly pointed out, terrain and obstacle factors impinge on the precision of ILS, and in many cases, can eliminate it outright. I am not sure what airport Bjorn is referring to, but I would guess that the terrain of Sweden may play a role on the accuracy of ILS there.
In europe, there is also a great deal of frequency congestion. Correct me if I am wrong Bjorn, but that probably isn't a factor in Sweden.
Then there is the economic factor. A standard CAT I ILS costs $1.2 million per runway end. I guess if Bjorn's hometown has only 6--7 flights per day, the politicians don't want to make the investment to upgrade the ILS capability--PROBABLY DUE TO COST v BENEFIT!
The Local Area Augmentation System (LAAS) is a GPS based system corrected for all precision and induced errors. It has been discussed on here before. The use of LAAS is said to be cheaper. More importantly it can make all runway ends usuable down to CATIIIC standards, anywhere in the world to great accuracy.
Until the day comes when GPS is accessible to precision approach standards, many airports will have to live with RNAV CAT I.