Latavish's Multiple Image Upload with Thumbnail Generation

[eluser]Mitja[/eluser]
Hi, very nice tutorial but i have problemm

Code:

foreach($_FILES as $key => $value)
{
    if( ! empty($key['name']))
    {
    $this->upload->initialize($config);
    $data['title'] = 'Files Upload!';
    if ( !$this->upload->do_upload($key))
        {

if ( !$this->upload->do_upload($key)) show me an error of

A PHP Error was encountered

Severity: Notice

Message: Array to string conversion

Filename: libraries/Upload.php

Line Number: 152

View is:

<tr><td>Fotka: &lt;input type="file" name="pluspayment_title_photo[]" /&gt;&lt;/tr>

what i am doing wrong?