Custom field checkbox always remains checked…..

This is really frustrating, I am trying to setup a custom field with a checkbox and no matter what I do the checkbox always remains checked even after unchecking it and updating the post…here is my code:

add_action('add_meta_boxes', 'jpg_affiliated');
function jpg_affiliated()
{
	add_meta_box('jpg_affiliated_staff', 'Who Was Involved?', 'jpg_affiliated_staff_callback', 'post', 'normal', 'default');
}
function jpg_affiliated_staff_callback($post)
{
	global $post;
    $custom = get_post_custom($post->ID);
	wp_nonce_field('jpg_affiliated_nonce', 'jpg_affiliated_nonce_field');
?>
	<p><strong>Select any staff that were involved in this event and what their role was.</strong></p>
    <div style="overflow:hidden;padding:0 0 10px 0">
        <table>
            <tr>
                <td width="10%"><input type="checkbox" id="jpg_team_member" name="jpg_team_member" value="Test"<?php if(get_post_meta($post->ID,'jpg_team_member', true ) == "Test" ){echo ' checked="checked"';}  ?>></td>
                <td width="40%"><label for="jpg_team_member">Test</label></td>
                <td width="50%">
                <select name="" id="">
                <option value="">Select role...</option>
                <option value="Primary Shooter">Primary Shooter</option>
                <option value="Second Shooter">Second Shooter</option>
                <option value="Third Shooter">Third Shooter</option>
                <option value="Lighting Assitant">Lighting Assistant</option>
                <option value="Photo Booth Coordinator">Photo Booth Coordinator</option>
                <option value="Marketing Coordinator">Marketing Coordinator</option>
                <option value="Studio Manager">Studio Manager</option>
                <option value="JPG Team Member">JPG Team Member</option>
                <option value="Photogrpaher">Photographer</option>
                </select>
                </td>
            </tr>
        </table>
    </div>
<?php
}

add_action('save_post', 'jpg_save_staff');
function jpg_save_staff($post_id)
{
	// Bail if we're doing an auto save
	if(defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) return;

	// if our nonce isn't there, or we can't verify it, bail
	if(!isset($_POST['jpg_affiliated_nonce_field']) || !wp_verify_nonce($_POST['jpg_affiliated_nonce_field'], 'jpg_affiliated_nonce' )) return;

	// if our current user can't edit this post, bail
	if(!current_user_can('edit_post')) return;

	// Probably a good idea to make sure your data is set
	if(isset($_POST['jpg_team_member'])){update_post_meta($post_ID, 'jpg_team_member', esc_attr($_POST['jpg_team_member']));}
}