Cannot submit a plugin

I've attached a screnshot of the error.

I'm trying to upload a plugin, with this text:

Project Title: Blank score with Eighth Rests Template
Short Project Name: Eighth Rests Template

Description:
This plugin will give you a blank, 32-measure, single-staff score pre-filled with 8th rests. A lot of us seem to find this to be a more useful starting point than the default whole rests.

I selected the "Plugin" radio button, and selected "Composing Tools" from the category list.

When I click "Preview" I get this error message:
Please only use alphanumeric characters for the project name.

I got this error message whether or not I attached a txt, png, or jpg file.

I'm running Firefox 10.0.2, under Windows XP.

fwiw, here is my plugin file, in case it's easier for someone else to upload it:

-----
function init()
{
// print("test script init");
};

function addNote(cursor, pitch, duration)
{
var chord = new Chord();
chord.tickLen = duration;
var note = new Note();
note.pitch = pitch;

chord.addNote(note);
cursor.add(chord);
cursor.next();
};

function addRest(i, score, cursor, duration)
{
var rest = new Rest(score);
rest.tickLen = duration;
cursor.add(rest);
cursor.next();
};

function run()
{
var score = new Score();
var n = 32;

score.name = "Blank Score";
score.title = "Title";
score.subtitle = "Subtitle";

score.appendPart();
score.appendMeasures(n);
var cursor = new Cursor(score);
cursor.staff = 0;
cursor.voice = 0;
cursor.rewind();
for (var i = 0; i < n*8; ++i) {
addRest(i, score, cursor, 240);
}
};

var mscorePlugin = {
menu: 'Plugins.Create Score with 8th Rests',
init: init,
run: run
};

mscorePlugin;