I have this on my passenger side.
They unfortunately are likely to have been knocked in the past.
If you imagine a small rail track with stoppers at each end, unfortunately it seems that one of your "stoppers" has been snapped by someone knocking the mirror and pushing them too far into the door, thus why they fold out correctly but not in.
Therefore the mirror will continue to retract past the point. You can disable the folding option if you are worried about damage, I think you hold the mirror button in for 10 seconds.
I don't know of any way of fixing/bodging it, as they appear to be sealed units ;(
Current Italian Cars:-
2004 Alfa Romeo GT 2.0 JTS
Previous Italian Cars :-
2003 Maserati 4200 Cambiocorsa
2006 Alfa Brera 2.2 SV JTS
1999 Alfa Romeo 156 2.4 JTD
2005 Alfa Romeo 156 2.0 JTS Veloce
2004 Alfa Romeo GT 1.9 JTD
2001 Alfa Romeo GTV 3.0 V6 Lusso
2002 Alfa Romeo 156 2.0 JTS