[Vwdiesel] Low oil pressure?

[Libbybapa at wmconnect.com]

Well, got the electronic oil pressure.  Cheap Actron gauge.  Shucks, it says 
20 psi cruising, 8 psi at idle.  Engine runs fantastic.  I haven't had a 
chance to swap the gauge yet and get a second opinion.  The needle doesn't have a 
very fluid motion, so it is somewhat suspect, but disconcerting none the less.
Please doublecheck my logic.
If low oil pressure is confirmed at head and filter flange, then the possible 
sources of low OP are:
Oil pump/relief valve
Main bearings
Rod bearings
Cam bearings
Intermediate shaft bearings
Turbo bearings (some play in shaft, so definitely suspect)
Did I miss anything?
What's the deal with swapping the intermediate shaft bearings?
I guess it's time to go look at the junk block.
The eninge had 180K miles on it, but ran great.  It always starts on the 
first rev. of the crank.  Considered rebuilding before installing it into my 
vanagon, but the coin came out heads.
Andrew