Hello,
after the crash I suffered while upgrading from 1.11.11 to 1.12.0 (all images gone) and the complete removal of all the leftovers to  freshly re-install everything, I've done the following:

installed 1.11.10 as a fresh install (this version was the last one worked fine)
upgarded to 1.11.11
upgraded to 1.12.1

everything seems fine except that, form 1.11.11, the pictures are displayed along with this error message (which is also a working link to the bigger image):

Warning: Wrong parameter count for imagettfbbox() in /home/eurovan3/public_html/administrator/components/com_rsgallery2/includes/img.utils.php on line 846

How can I solve this?

thanks in advance