redmine API: cannot GET issues.json with curl

Question

When I issue the following command, I got a HTTP/1.1 401 Unauthorized error:

curl -v -XGET -u admin:admin http://my_projects.heroku.com/projects/PROJECT_NAME/issues.json

Any idea ?

UPDATE

curl -v -XGET http://my_projects.heroku.com/news.json
curl -v -XGET http://my_projects.heroku.com/projects.json

are working fine (I mean, I do not have 401 error but obviously my private projects is not listed). Seems that the permissions of my issues are not correctly set...