Hello Bob,
"I wonder why the second problem happened? All of the numerical data (for ratings of 1 - 5) dissapears?"
What version of the questionnaire module are you using? Disappearing data for 'rating' items was a bug in an old version. The latest version solves this problem.
Have a look at this thread:
http://moodle.org/mod/forum/discuss.php?d=28427
Questionnaire (plugin)
CSV exports garbled characters in Japanese?
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