Are you using the PHP GD Libary? This addon currently doens't support ImageMagick.
Which Version of the PHP GD Libary is installed?
If you are currently not using the PHP GD Libary or it is older than GD2, please install/update GD and try it agein.
If you are using GD2, please send me
via PN the output of
PHP Code:
<?php
phpinfo();
and the output after refreshing the css-sprites via admincp.
If possible, please check your php error-logs if if some errors related to the
sprite.php occurred.
Big Big Thanks for the nice feedback