foo.JPG is sent as application/octet-stream
 

It appears that files with .JPG suffixes (as opposed to .jpg) are not recognised correctly as image/jpeg even though I have tried various incantations of the sort:-

JPEG,jpeg,jpe,JPG,jpg = image/jpeg

in $SERVER_ROOT/conf/mime.properties

Is this a feature or a bug?

It is a bug, MIME configuration will be converted lowercase, but treat file suffix case sensitive.

Will make file suffix case insensitive, thanks.

Work around is to use "ForceType" along with a matching context, or use mod_rewirte to force mime type.