Boac,
every time i've flown the 06 procedure i've experienced the same as you...a thought that springs to mind is perhaps the VOR signal is right on the max tolerance of +/- 3deg(or whatever it actually is). Although some may consider it a little unorthodox, I've found that by staying in HDGSEL on the intercept until slightly through the Localiser, and selecting VOR/LOC to pick it up from 1/2 a degree from the southern side results in more satisfactory tracking. Just my humble opinion, but when picking up the Loc from the northern side it does seem like the a/p takes an age to get the Loc bar dead centred, after VOR/LOC is actually annunciated. Maybe the beam is a bit dodge on the northern side? Terrain affecting it?
Bumblebee