[Plugin: GeOSM2] Plugin doesn't work / new install / gives error and garbage

New install. Selected a post with known geo tags in it:

Warning: fopen(/home/***********/public_html/wp-content/plugins/geosm2/cache/tiles/14-4502-6124.png) [function.fopen]: failed to open stream: No such file or directory in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 51

Warning: curl_setopt_array(): supplied argument is not a valid File-Handle resource in /home/**********/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 58
�PNG ��� IHDR���������k�XT�� etc, etc.

So, I create cache directory and cache/tiles directory. Make them world writable. Now I get this:

Warning: imagecreatetruecolor() expects parameter 1 to be long, string given in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 121

Warning: imagecopy() expects parameter 1 to be resource, null given in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 123

Warning: imagecopy() expects parameter 1 to be resource, null given in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 127

Warning: imagepng() expects parameter 1 to be resource, null given in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 129

Warning: imagedestroy() expects parameter 1 to be resource, null given in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 131

Warning: imagecreatetruecolor() expects parameter 1 to be long, string given in /home/*****/public_html/wp-content/plugins/geosm2/geosm2_widget.php on line 121

http://wordpress.org/extend/plugins/geosm2/