You are right. The bug exist in the two lines of code inside of $('.ui-pg-selbox',”#”+pgcnt).bind('change',function() {…}.:
if(tp) { $('.ui-pg-selbox',ts.p.pager).val(this.value); }
else if(ts.p.toppager) { $('.ui-pg-selbox',ts.p.toppager).val(this.value); }