media sources for users not working??

OK, so I have three different media sources that I want to make available to different user groups. Logged in as default admin, that works OK and I can choose from the drop-down above the file tree what media source I want to see. however, for anyone else logging in, this doesn't work. I have not restricted any of the media sources, yet, when e.g. a member of the editors group logs in, all they can see in the dropdown is a "1" which happens to be the id of the media source I want them to see, but it should say the name of the media source. I also want them to be able to see another media source, but whatever I try, I can't get them to see it. I have flushed permissions and cleared the cache multiple times, yet no joy. Even worse, if I start restricting a media source to a specific user group, the files actually disappear from their file tree?? Any ideas what I am doing wrong?

Thanks!

update:
- it seems this bug is not fixed for me, even though I do have the settings mentioned
http://tracker.modx.com/issues/6470??
- also, I have checked the default the "Default Media Source" system setting which actually shows as "1" and when edited is just blank?

any ideas what's going on here?

another update:
First I updated to Revo 2.2.7 as there was some hints about bugs related to media sources in older versions. That didn't do much.
Then, I finally worked out what the problem was: my editors didn't have the "source_view" setting ticked in the "Editor" access policy. I have now ticked this and now editors can view the list of media sources. Hope this helps someone, took me ages to work out what was going on