I've been trying to work out why I'm getting smooth scrolling on some of my page links, but not others, but after a bit of debugging, it became clear.
avia_smoothscroll uses jQuery to return an array of named anchors using $(hash), but it appears that jQuery won't return named anchors with periods in them, which is strange as it appears to be part of the spec: http://www.w3.org/TR/html4/types.html#h-6.2
Anyway, changing the following line...
var container = $(this.hash);
... to this...
var container = jQuery('a[name="' + this.hash.substr(1) + '"]');
... fixes the issue.
This page demos links with periods and the altered code: