Have the same problem : file manager can upload but can’t insert “image” files (.png, .gif or .jpg) in publish (custom text field).
But it can with text, html, tiff and pdf files…
I found this strange code in a “edit” page with the file manager opened :
<div title="https://ellislab.com/asset/images/pronet-logo/|ADQCAHIER.pdf">http://www.something.org/themes/cp_global_images/default.png</div>
<div title="width="200" height="133"">http://www.something.org/themes/cp_global_images/default.png</div>In the div title you have the path to the pdf file (that I can insert), but there seems to be a mix up in the .jpg file information : the width and height information should not be there while the path of the image should probably be in the div title…
Tried the thing with the “mimes”, but I upgraded directly from 1.6.9 to the last build, so it did not changed anything. Any browser on Mac.