At first, thank you all and especially ixtab for his troublesome work!
I already had the current jailbreak and previous JBPatch version on my Kindle PW with firmware 5.3.1 and because new JBPatch was released I updated to firmware 5.3.3 and JBPatch 3.2. After 'refreshing' kindlet-jailbreak and localization files, all was well and functional again, even all my font, margin, etc. settings were restored.
Now trying the new justification setting in hyphenation patch.
Changing to 'ragged justification' in my mobi-files (floating text) does not make a difference, the text stays 'fully-justified'. After changing the option I did a 'System/Restart Framework' in JBPatch, also a 'Menu/System/Restart' effects nothing.