Yet another upload_path problem

[eluser]PoWah[/eluser]
I have upload_path defined

Code:

$config['upload_path'] = realpath(BASEPATH.'../static/images/katalogas/kategorijos/');
$this->load->library('upload', $config);

when I echo it I see "C:\wamp\www\ptvs\static\images\katalogas\kategorijos" and it is correct! Why I get an error "The upload path does not appear to be valid." ? I'm now coding on WAMP server under Windows.. tried to search the forum and I saw tons of similar posts but ... :/