php thumb generation problem

Hi,

I am working on project in which i am creating gallery from uploading images and creating their thumbs using phpThumb (phpThumb() object).The image uploading is working well but when it try to create thumb it gives ########
phpThumb() v1.7.9-200805132119 "" does not exist ######### error
The configuration of my server is :
Phpthumb version : 1.7.9-200805132119
PHP Version : 5.2.5
GD Version : bundled (2.0.34 compatible)
Server Software Version : Microsoft-IIS/6.0
memory_limit: : 128M both local and master
curl version 7.16.0
No Imagemagick and EXIF installed

The script i am using is :
############################
/* uploading script goes here and its is succesfully uploading images */
require_once("phpThumb/phpthumb.class.php");
$phpThumb = new phpThumb();
$phpThumb->src = "../images/home/10/temp.jpg"; // uploaded images
$phpThumb->config_prefer_imagemagick = false;
$phpThumb->config_output_format = "jpg"; // same error if i use it as png and upload png image
$phpThumb->config_error_die_on_error = true;
$phpThumb->config_temp_directory = "/phpThumb/cache/"; // I even tried current directory and even directory containing images
$phpThumb->config_cache_directory = "/phpThumb/cache/"; // I even tried current directory and even directory containing images
$phpThumb->sia = "small_1.jpg";
$phpThumb->config_cache_disable_warning = false;
$cacheFilename ="small_1.jpg";
$phpThumb->cache_filename = "../images/home/10/".$cacheFilename;
$phpThumb->w = 80;
$phpThumb->h = 80;
$phpThumb->q = 100;
$phpThumb->zc = 100;
if(file_exists($phpThumb->cache_filename))
{
unlink($phpThumb->cache_filename);
}
if(!is_file($phpThumb->cache_filename))
{
if ($phpThumb->GenerateThumbnail())
{
$phpThumb->RenderOutput();
$phpThumb->RenderToFile($phpThumb->cache_filename);
}
else
{
die(’Failed: ’.$phpThumb->error);
}
}
######################################################################################
Directory structure is like this :
/admin/phpThumb/ //php thumb packages
/admin/addimages.php //script uploading an image and creating thumb
/images/homes/10/ // directory creating images

I tried lot of way to resolve this issues but still gives the same errror ######## phpThumb() v1.7.9-200805132119 "" does not exist ######### error .
Can you please help me and make clear why this is happening and what this error means.Looking for your genius advice..I’ll be so oblique.