scroller sometimes add height automatically when enable infinite scroll and navigate back from another panel

[rancpine]

demo: http://fiddle.jshell.net/2fx55rf6/42/show/

In demo I've loaded: af.ui.base.min.css/ appframework.min.js/ appframework.ui.min.js/ af.scroller.js

Way to reproduce the situation:

1. open the demo, scroll the "#opp" panel to bottom (wait util it says:"This was loaded via inifinite scroll More Content")
2. check the css of div.afScrollPanel: ... matrix3d( ... ,-596, 0, 1);
3. click "filter" button, which bring us to another panel "#opp-filter"
4. navigate back from "#opp-filter"
5. now div.afScrollPanel: ... matrix3d( ... ,-648, 0, 1);

[imaffett]

Verified this. I'll try to look into it if I get time.