Deleting single item with submit from database results in two ID's and strings - sql

Question

When I try and delete an entry from the code below it seems to spew out two array values with different index numbers and will not delete the entry. If I click multiple times it finally gets the correct ID but only by some random chance.
Using echo var_dump($deleted) results in something like:
String(2) "10"
String(1) "7"
These can vary and seems to be random.
I have reduced my whole plugin to just the code below thinking that maybe some other submit query might be interfering with it. And still I get two ID's with unknown string assignments.
Any ideas?
function myplugin_update_page(){
global $wpdb;
$update_page_list = $wpdb->get_results('SELECT * FROM wp_update_page');
$active = $wpdb->get_var("SELECT * FROM wp_update_page WHERE active='on'");
echo '<form method="post" action=""><table>';
foreach ( $update_page_list as $update ) { ?>
<tr>
<td><input type="image" src="<?php echo plugin_dir_url(__FILE__).'images/delete.png'; ?>" name="delete[]" value="<?php echo $update->ID; ?>" /></td>
</tr>
</table>
</form>
</div>
<?php
}
if(isset($_POST['delete'])) {
$delete = $_POST['delete'];
foreach ($delete as $deleted) {
$wpdb->query("DELETE FROM wp_update_page WHERE ID = $deleted");
}
echo "<script type='text/javascript'>window.location=document.location.href;</script>";
}
}