I have stripped down the xml that is returned to be more simple, figuring something would make it work, but nothing has worked. Here is the code I am trying now:

var mystr = "<?xml version='1.0' encoding='utf-8'?><top><rowset><row id='1'><LOG_ID>69</LOG_ID><EVENT_ID>0</EVENT_ID><SUMMARY>Test 8</SUMMARY><LOCATION>here</LOCATION><DTSTART>dtstart</DTSTART><TRANSACTION_DATE>Transdate</TRANSACTION_DATE><MESSAGE>message</MESSAGE><SUCCESS>N</SUCCESS></row><row id='2'><LOG_ID>68</LOG_ID><EVENT_ID>0</EVENT_ID><SUMMARY>Test 7</SUMMARY><LOCATION>here</LOCATION><DTSTART>Startdate</DTSTART><TRANSACTION_DATE>Transdate</TRANSACTION_DATE><MESSAGE>Message</MESSAGE><SUCCESS>N</SUCCESS></row></rowset></top>";
            $("#logViewer").jqGrid({
                //url:'cronservlet/log',
                //datatype: 'xml',
                datatype: 'xmlstring',
                datastr : mystr,
                xmlReader: {
                  root:'rowset',
                  row:'row'
                },
                colNames:[
                    'Log ID',
                    'Event ID',
                    'Summary',
                    'Location',
                    'Start Date',
                    'Transaction Date',
                    'Message',
                    'Success'],
                colModel:[
                  {name:"logid", index:'logid', xmlmap:"LOG_ID"},
                  {name:"eventid", index:'eventid', xmlmap:"EVENT_ID"},
                  {name:"summary", index:'summary', xmlmap:"SUMMARY"},
                  {name:"location", index:'location', xmlmap:"LOCATION"},
                  {name:"dtstart", index:'dtstart', xmlmap:"DTSTART"},
                  {name:"transdate", index:'transdate', xmlmap:"TRANSACTION_DATE"},
                  {name:"message", index:'message', xmlmap:"MESSAGE"},
                  {name:"success", index:'success', xmlmap:"SUCCESS"}
                ],
                sortname: 'logid',
                sortorder: 'desc',
                rowNum: 10,
                pager: jQuery('#pager'),
                viewrecords: true,
                imgpath: 'js/jqgrid/themes/basic/images',
                caption: 'Exchange Cron Log'
            });