Upload filetype not allowed??

[eluser]123wesweat[/eluser]
hmmm,

in Upload.php in function is_allowed_filetype() i added

Code:

foreach ($this->allowed_types as $val)
        {
            echo $val;

and when i upload a jpg it returns

Code:

doc
docx
gif
jpeg

when i try to upload a .txt

Code:

doc
docx
gif
Array ( [error] =>

The filetype you are attempting to upload is not allowed.
)

Now the strange thing is when i use

Code:

$config['allowed_types'] = 'txt|text';

it does upload the .txt file.

Is there a particular order we should follow??