Tags
If your tags do not display properly, adjust the values of the printAllTagsAs_zb function at the bottom of the _sidebar.php file.
'cloud', 'taglist', 'abc', false, true, 2.5, 70, 25, null
Lower the 70 figure if you have few images with each tag.
Contact form
The contact form may require a captcha. Do not forget to enable a captcha engine or you will get a warning on the page.
Homepage random images
The homepage random layout can only be chosen if the image_album_statistics is enabled.