Hey harraldsson,
I had a very similar issue with 6.5.3 and it was persistent even after the 6.5.5 update. What solved my issue was what was recommended in the last post as well: Trashing my preferences. I had done so before, but I always overwrote my four config files to have my configurations. Turned out the problem was in one of those.
So I recommend: Trash your preferences and use the default configuration files for a while… if it works without crashes, manually set your settings.