virtualmin and CORS

hello -

i am getting this nasty looking message when running over a proxy-server:

XMLHttpRequest cannot load http://foo.bar:12354/. 
   No 'Access-Control-Allow-Origin' header is present on the requested resource. 
   Origin 'http://foo.bar' is therefore not allowed access.

some forums have suggested that apache needs to have a CORS setting. i tried putting

Header set Access-Control-Allow-Origin "*"

in the dot-access file but that didnt work.

any thoughts?