It seems these 2 items do not work well together. When they are both used the Frozen column header is enlarged and has a scroll. See here: http://www.lafvb.com/jqGrid/products.php

I tried looking at it and the height changes in the setFrozenColumns: function() {

It is on these lines:

a(b.grid.fhDiv).append(c).mousemove(function(a) {