jQuery Grid Plugin - jqGrid

I've started having IE 7 complain (but only intermittently so it seems like possibly a timing issue????) if I use a jQuery object as the value of the grid's pager attribute.   The docs indicate you can use either   

pager: jQuery('#nameOfMyPager')   OR  

pager: '#nameOfMyPager'

But if I use the jQuery version IE 7 complains some of the time on the pginp = line in setPager of grid.base.js:

setPager = function (){
var sep = "<td class='ui-pg-button ui-state-disabled' style='width:4px;'><span class='ui-separator'></span></td>",
pgid= $(ts.p.pager).attr("id") || 'pager',
pginp = (ts.p.pginput===true) ? "<td>"+$.jgrid.format(ts.p.pgtext || "","<input class='ui-pg-input' type='text' size='2' maxlength='7' value='0' role='textbox'/>","<span id='sp_1'></span>")+"</td>" : "",

giving "Error: object doesn't support this property or method".

I can (without changing anything in the page/code) hit Ctrl-Refresh and sometimes have it load fine without that error and other times get the error which does prevent loading of the grids.  I've experienced it on lots of different grids with different configurations.   But fortunately if I just change it to use the string version of setting pager attribute, it doesn't seem to ever give the error. 

Just wondering if anyone else has ever seen this or would have any ideas on it's cause.  If I can get time I'll try to replicated it with a simple test cased based on one of the demos. 

Lynn