Some accented characters dont get typed in some scribus objects

In scribus (1.5 svn version compiled on ubuntu), the canvas editing (wysiwyg editing) doesnt enable anymore to type in some accented characters as
ê, î, ô, û, ï, ö, ü, Ê, À, Ô etc
These require 2 keystrokes : ^ + e, ¨ + i, ^ + E, ...

Other characters are typed in ok : é, è, à. These only require one keystrike.

I have tried with Qt5.3 pre-RC version and its not fixed yet.

I dont know Qt a lot so i'm not sure with the "components" i specified for this report.