Alex111,
May I suggest you use extreme caution with this LNAV...
It is still much better in my opinion to use VOR/LOC or HDG SEL. with raw data cross reference for any Non precision approach. Actually, always cross check with your raw data, also in LNAV.
I've had way to many map-shifts on the B737EFIS.
Just GOP. Good Operators Practice.
Mind you, I do think that on the NG with dual GPS, LNAV will be much more accurate and reliable, compared with the Classic.