I’m also getting a lot of strict notices:
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method GoogleSitemapGeneratorLoader::Enable() should not be called statically in /wp-includes/plugin.php on line 429
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method GoogleSitemapGeneratorLoader::Enable() should not be called statically in /wp-includes/plugin.php on line 429
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method GoogleSitemapGeneratorLoader::RegisterAdminPage() should not be called statically in /wp-includes/plugin.php on line 429
Strict Standards: Non-static method GoogleSitemapGeneratorLoader::GetBaseName() should not be called statically in /plugins/google-sitemap-generator/sitemap.php on line 114
…and more on the sitemap options screen.