And the problem is back again!
From the about 900 jpg files are about 125 files with bitsize 24, all the others are 8.
Bitsize 8 largest dimension 640×640=3276800
Bitsize 24 largest dimension 640×510=7833600
Largest filesize jpg is 25 kb
Is it the amount of calculations?
Or are files like wmv or pdf causing the problems?