Call the cssSelector method on your createSeekbar function after append of progress bar will solve your issue.
createSeekbar : function(divid){
$('.jp-progress').remove();
var progressbar,seekbar,playbar;
progressbar= $('<div/>',{
"class" : "jp-progress"
}).insertAfter("#"+divid);
seekbar= $('<div/>',{
"class" : "jp-seek-bar"
}).appendTo(progressbar);
playbar= $('<div/>',{
"class" : "jp-play-bar"
}).appendTo(seekbar);
//Additional code appended here
//..............................................
$("#jquery_jplayer").jPlayer({
cssSelector:
{
seekBar: '.jp-seek-bar',
playBar: '.jp-play-bar'
}
}