Hello Vilas,
This is a good thread, you have authored several very good posts.
At our company we do not arm APPR until with in 100' of the FAF altitude. "Once the aircraft is established in NAV or LOC and within 100 feet of the FAF altitude, the APPR button may be armed ...."
This has been explained to us because of anomalies in coding contained in our FMGC. This requirement does not pertain to -V approaches because of different coding. (Which may be a North America issue)
As others have posted, if APPR is armed prior to being within 100' of FAF altitude the airplane does "unusual" things.
Regards,
Mongo.
(Lexxie747 your comments are noted as is your retirement. I've instructed on T-37's and flown F-16's in combat, plumbed the 727 and co-piloted the 777, was a Captain on the Jurassic 737 and Captain on the A-320. True professionals learn their aircraft as well as honing their craft - enjoy your retirement, it is well deserved.)