When two HTMLText widgets are in the same form, none is saved

Have a document type ("MyDoc") with 2 fields. For example f1 and f2
In the create/view/edit layouts, have:
Title
Description
f1
f2

Save (we're in the Studio), update the server, create a "MyDoc" document. Put any value in f1 and f2 (or just in one), and "Save"
=> Fields are not saved

If the layout displays only one HTMLText, it is ok (but we need 2)

Tested with versions 572 and nuxeo-cap-5.7.3-I20130911_0116-tomcat