getimagesize() not working ... image exists, error says it doesnt :(

[Eclectic]

I am using the latest version of PHP and GD (reinstalled both today -
march 29 2005) and am using GD to create thumbnails on the fly. I am
having no issues with GD, however, I am now trying to retrieve the
width and height of other images withought ANY sucess ... I am
recieving the same error repeatedly :
"... failed to open stream: No such file or directory ..."

I am replacing spaces with '%20' as PHP.net suggests, and have parsed
local and full paths (which all work when entered into a browser) with
no success.

here is my code :

$image=str_replace(' ','%20',$_GET["image"]);
$imageinfo = getimagesize($image);
$w=$imageinfo[0];
$h=$imageinfo[1];

why doesnt this work? please help!

Cheers in advance,

Eclectic.