Great! Finally after flashing back to 5.1.2, installing it worked (am at 5.3.2, now). however, the screen rotation does not work! so when landscape mode is activated, change any settings does not work because the position of clicking are wrong! so only portrait mode works. that is a real pity because pdfs and djvus normally have to be read in landscape mode with fit to width because they are simply way to small in portrait mode. furthermore it is unfortunate that other zoom options are not possible.
Still having djvu support is truly amazing!!! Thanks to everybody who was and is working on it!