Here's a jsbin that seems to work with both of your sample files (although I haven't checked very closely).

http://jsbin.com/cuy/1/edit?js,output

The parsing and drawing code is here

var canvas = document.getElementById('canvas');      
// Create Chart
chart1 = new Scribl(canvas, 770);
chart1.laneSizes = 18;

// grab gff data
var records = $("textarea").html().split('\n');

for (var i=0; i < records.length; i++) {
 // ignore comments
 if (records[i][0] == '#') continue;
 // parse gff fields
 var fields = records[i].split("\t");
 var seqid  = fields[0],
     source = fields[1],
     type   = fields[2],
     start  = parseInt(fields[3]),
     end    = parseInt(fields[4]),
     score  = fields[5],
     strand = fields[6],
     phase  = fields[7],
     attr   = fields[8];

 // add gene to chart with desired attributes
 var gene = chart1.addGene(start, end-start, strand);
 gene.name = type;
}

// Draw Chart
chart1.draw();