I think it would be best that you should disable all other MP plugins to reduce unnecessary extensive logging increasing the logs.If it's the same behavior with pulse-eight tools, it's most likely problem with the libcec (or buggy Philips CEC). You could ask P8 for info, or if you want me to take a look, please add some logs.
Thanks Tuomaa for your offer to look at my logs. This is not happening at my main place, but on my weekend-place. I will be there next on weekend of 1. December. I will then try to create a logfile.
I assume that I should enable extensive logging in the plugin-configuration and then start MP and press the info-key once. It will then loop with detecting info-pushes, until I press another key.