jQuery Grid Plugin - jqGrid

I have made the 3rd visible column (the one with added jqg_note class) auto height and I have a few rows at the start that are more than one line high.  Problem is endless scroll does not show the last few rows.  If I reverse the sort order, then all rows show.

Tried this on Chrome, Firefox and iPad, all showed the same bug.

I tried changing the jqgrid height, but no success.

CODE & DATA

<style type="text/css">
#notes_grid tr.jqgrow .jqg_note { /* Enable word wrap */
    white-space: normal !important;
    height:auto;
}
#notes_grid tr.jqgrow td { /* Cells align at top */
    vertical-align:text-top;
    padding-top:2px;
}
#notes_grid {font-size:1.2em !important;}
</style>

$("#notes_grid").jqGrid({
url:'frames/notes_list.php?job='+job_id,
datatype: 'json',
mtype: 'GET',
colNames:["id","user_id","User", "Date & Time", "Note"],
colModel:[ {name:'ID',index:'ID',width:1,hidden:true,key:true},
{name:'USER_ID',index:'USER_ID',width:1,hidden:true},
{name:'USERNAME',index:'USERNAME',width:100},
{name:'CREATE_DATE',index:'CREATE_DATE', width:150},
{name:'NOTE',index:'NOTE', width:432,sortable:false, classes:"jqg_note"} ],
rowNum:15,
height: 300,
forceFit: true,
gridview: true,
hidegrid: false, // Remove the hide button
scroll: true, // Endless scroll
hoverrows:false,
// Events
onCellSelect : function(rowid, index, contents, event) { if (rowid) fill_job_notes_details($(this).jqGrid('getCell', rowid, 'USER_ID')); },
ondblClickRow: function(rowid) { edit_note(rowid);}
});

JSON DATA:

{"page":"1","total":3,"records":"32","rows":[{"id":"1","cell":["1","1","Justin Levene","2012-08-07 10:14:38","This is Justin&#039;s first note..."]},{"id":"2","cell":["2",null,"Administrator","2012-08-07 10:14:38","This is an Admin note"]},{"id":"3","cell":["3","1","Justin Levene","2012-08-07 10:14:38","Another Justin note"]},{"id":"4","cell":["4","1","Justin Levene","2012-08-16 13:52:31","This should be the last note"]},{"id":"5","cell":["5",null,"Administrator","2012-08-16 14:32:55","Justin is watching me"]},{"id":"6","cell":["6","1","Justin Levene","2012-08-16 14:38:42","This is a test to see how long I can write for. I will write quite a bit of drivel and rubbish just to make this note quite large and long winded. God this is betting dull, but it is for a reason...."]},{"id":"7","cell":["7","1","Justin Levene","2012-08-16 14:40:10","This is a test hi"]},{"id":"8","cell":["8","1","Justin Levene","2012-08-16 14:42:26","Yet another note."]},{"id":"9","cell":["9","1","Justin Levene","2012-08-16 14:44:26","Just phoned Justin who said that I can take my invoice and shove it up my arse."]},{"id":"15","cell":["15","1","Justin Levene","2012-11-09 13:56:31","This should be the last note"]},{"id":"16","cell":["16","1","Justin Levene","2012-11-09 13:57:22","Ok I changed my mind and wanted to do a few more notes, so here goes. This is quite a long one so lets see how this one looks, I am not going for a record but you never know."]},{"id":"17","cell":["17","1","Justin Levene","2012-11-09 13:58:21","Another long note I think, this is so that I can test the scrolling and if I have a bug. I hate bugs, they give me so much grief and hardship, why can&#039;t coding just go without a hitch, hey ho, lets see."]},{"id":"18","cell":["18","1","Justin Levene","2012-11-09 13:58:43","Oh goody there was no bug. I am good you know"]},{"id":"19","cell":["19","1","Justin Levene","2012-11-09 13:59:14","This is note 14, I need to do over 20"]},{"id":"20","cell":["20","1","Justin Levene","2012-11-09 13:59:24","This is note 15"]}]}