The problem seems to be in that sbCustomSelect plugin. It works fine as long as you initiate it once on the page (you can have it applied on multiple elements, they just need to be under one single selector).
Initiating it twice like this:
$('.row.heh select').sbCustomSelect();
$('.row.actionbox select').sbCustomSelect();
Will make the jumping occur, like can be seen here: http://jsfiddle.net/niklasvh/Qker9/7/
You can get the same functionality by combining them into one single selector and initializing the plugin only once:
$('.row.heh select, .row.actionbox select').sbCustomSelect();
And the plugin works fine:
http://jsfiddle.net/niklasvh/Qker9/8/