Image uploads failing

Whenever I upload an image with your plugin enabled, I get these errors:

[06-Apr-2013 20:03:08] PHP Warning:  imagecreatefrompng(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 719
[06-Apr-2013 20:03:08] PHP Warning:  imagesx() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 722
[06-Apr-2013 20:03:08] PHP Warning:  imagesy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 723
[06-Apr-2013 20:03:08] PHP Warning:  getimagesize(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 819
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 820
[06-Apr-2013 20:03:08] PHP Warning:  imagecopyresampled() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 831
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 807
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 809
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 811
[06-Apr-2013 20:03:08] PHP Warning:  imagecopymerge() expects parameter 2 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 813
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatefrompng(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 719
[06-Apr-2013 20:03:08] PHP Warning:  imagesx() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 722
[06-Apr-2013 20:03:08] PHP Warning:  imagesy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 723
[06-Apr-2013 20:03:08] PHP Warning:  getimagesize(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 819
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 820
[06-Apr-2013 20:03:08] PHP Warning:  imagecopyresampled() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 831
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 807
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 809
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 811
[06-Apr-2013 20:03:08] PHP Warning:  imagecopymerge() expects parameter 2 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 813
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatefrompng(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 719
[06-Apr-2013 20:03:08] PHP Warning:  imagesx() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 722
[06-Apr-2013 20:03:08] PHP Warning:  imagesy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 723
[06-Apr-2013 20:03:08] PHP Warning:  getimagesize(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 819
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 820
[06-Apr-2013 20:03:08] PHP Warning:  imagecopyresampled() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 831
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 807
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 809
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 811
[06-Apr-2013 20:03:08] PHP Warning:  imagecopymerge() expects parameter 2 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 813
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatefrompng(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 719
[06-Apr-2013 20:03:08] PHP Warning:  imagesx() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 722
[06-Apr-2013 20:03:08] PHP Warning:  imagesy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 723
[06-Apr-2013 20:03:08] PHP Warning:  getimagesize(10): failed to open stream: No such file or directory in /www/wp-content/plugins/image-watermark/image-watermark.php on line 819
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 820
[06-Apr-2013 20:03:08] PHP Warning:  imagecopyresampled() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 831
[06-Apr-2013 20:03:08] PHP Warning:  imagecreatetruecolor(): Invalid image dimensions in /www/wp-content/plugins/image-watermark/image-watermark.php on line 807
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 809
[06-Apr-2013 20:03:08] PHP Warning:  imagecopy() expects parameter 1 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 811
[06-Apr-2013 20:03:08] PHP Warning:  imagecopymerge() expects parameter 2 to be resource, boolean given in /www/wp-content/plugins/image-watermark/image-watermark.php on line 813

Disabling it again fixes the problem.

Looking in the database, the url stored is “10”, the ID of the image, but not the url.

http://ww.wp.xz.cn/extend/plugins/image-watermark/