"You don't have Javascript enabled" and other side problems with HS widget config "Resizable" on

I was hit by this issue which seems to raise in different situations, as it appears in the confusing thread there
http://drupal.org/node/734178

One is now well defined and corresponds to the issue in subject here:
http://drupal.org/node/734178#comment-3359588

There is definitely a problem with HS configuration "Resizable" option. Many problems went out after unchecking this option (including file auto-preview in file Framework)

Note that the issue arose only for anonymous and non admin users though...