Hello, I have a file upload page, and I've had it working fine, it was beautiful

Anyway, the powers that be moved hosts... and it doesn't work now. The file name is correct, the directory where it's going on the server is correct (checked through prints etc.). I've changed the dir to 777 (is that right?) and this is what I get on the print_r($_FILES); line: Array ( [userfile] = Array ( [name] = amy.txt [type] = text/plain [tmp_name] = /tmp/phpccPHUE [error] = 0 [size] = 39 ) ) And the file is not uploading - I'm getting an error on the line: if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) { And yet, you'll notice the line above clearly states I get '0' error?!?! I can't work it this one out... any helpful hints? Please? Many many thanks, Amy