I created the JPG myself, and I don't know if it's ReviewPost or what. I got that error with GD1 or GD2, when I switch to ImageMagick I get a different error:
Error creating thumbnail! Error code: 127
Command: "" -size 80x80 -quality 70 -geometry 80x80 /home/******/public_html/productreviews/data/30/1108hijackpro2icon-thumb.jpg
Can anybody please tell me what the problem is? All libraries are installed properly according to my host.