Problem solved - at least a workaround
It seems that this latest version of the Feedback module requires a change in the roles settings.
I got a hint for this workaround in this discussion:http://moodle.org/mod/forum/discuss.php?d=108264
So, to make it possible to add questions you need to:
- set up a Feedback activity
- before saving, click on the "Locally assigned roles" tab
- click on 'Teacher'
- click on your own name, and add yourself to the left hand column
- go back to the Settings section, and save
This workaround is not necessary in a moodle system I downloaded via CVS
last week (27th Oct, 2008), which included a download
of the Feedback module. So, I think this is a bug: it should not be necessary to change the 'Locally assigned roles" in order to use an activity module in a 'normal' way.