Included/permitted file types

I need to let a non-admin WP user manage and upload employees phone-number list in a form of web/html pages obtained/generated by MS Excel. It contains .htm, .css and .xml files. Both admin and an ordinary user can successfully display and manage the files using the shortcode:
[fileaway type=”table” sub=”Phonelist” directories=”on” manager=”on” prettify=”off” include=”.htm,.css,.xml”]
(I have setup the Manager Mode enabled for all possible user roles.)
As the WP administrator I can upload all of the files using simply:
[fileup sub=”Phonelist”]
But a non-admin user (editor, author, contributor) is not permitted to upload files with the .htm extension! I have tried:
[fileup sub=”Phonelist” showto=”administrator,editor,author,contributor,subscriber” filetypes=”htm,html,css,xml” action=”permit”]
But no success. The .css and .xml files do get uploaded but no way to upload any .htm file.