I forgot to add that I also get these errors when I run gThumb from a terminal:
(gthumb:31542): GLib-CRITICAL **: Source ID 745 was not found when attempting to remove it
(gthumb:31542): GLib-CRITICAL **: Source ID 748 was not found when attempting to remove it
They however only appear when gThumb generates thumbnails. When browsing images in full screen they do not pop up, but extremely slow image rendering persists. So I do not think they are related.
I forgot to add that I also get these errors when I run gThumb from a terminal:
(gthumb:31542): GLib-CRITICAL **: Source ID 745 was not found when attempting to remove it
(gthumb:31542): GLib-CRITICAL **: Source ID 748 was not found when attempting to remove it
They however only appear when gThumb generates thumbnails. When browsing images in full screen they do not pop up, but extremely slow image rendering persists. So I do not think they are related.