I'm test the plugin on my website.

http://www.deister-aquaristik.de/joomladeister/index.php/stockliste/tanganjika

Need single thumbnails for the site but there is no thumbnail, only the Textlink.
The file-attributes are 755
There are no problems with the lightbox. When you click on the Textlink is working great.

1.Box: {artsexylightbox singleImage="images/tanganjika/alto_cal_black/thumb.png" showSingleImage="false" path="images/tanganjika/alto_cal_black"}{/artsexylightbox}

Shows also the thumbnail in the gallery

2.Box:{artsexylightbox singleImage="images/tanganjika/alto_cal_yellow/alto_cal_ndode.png" path="images/tanganjika/alto_cal_yellow" previewWidth="130"}{/artsexylightbox}

3.Box:{artsexylightbox singleImage="images/tanganjika/alto_comp_chisanse/alto_comp_female.png" autoGenerateThumbs="true" previewWidth="100" showSingleImage="false" path="images/tanganjika/alto_comp_chisanse"}{/artsexylightbox}

4.Box: No problems with
{artsexylightbox path="images/tanganjika/cahlino_ndobhoi" previewWidth="100" autoGenerateThumbs="true"}{/artsexylightbox}

5.Box:{artsexylightbox singleImage="images/tanganjika/cyphoti_frontosa_blue/cypho_fron_moba_male.png" previewWidth="130" autoGenerateThumbs="true" path="images/tanganjika/cyphoti_frontosa_blue"}{/artsexylightbox}

I can't find the mistake