I have just seen the page number issue and will be taking that up with Adobe. No solution I can offer at the moment. I have page numbers defined and am seeing the ones you see plus mine in the wrong place.
As to the wrong characters, try the sample projects and see if you get them there. If not, then are the characters replacing something else or are they additional. Perhaps you could add a screenshot?
See www.grainge.org for free RoboHelp and Authoring information.

@petergrainge
Help others by clicking Correct Answer or Like if helpful. Found your answer elsewhere? Share it here.