Ok, interesting.
I have an _old_ version: the one which comes with Ubuntu 14.04, labelled 1.4.2. Funnily, while the source folder is called 1.4.2, the window title, when I open the program tells me 1.4.3svn...
I have a _new_ version: comes with Ubuntu 14.10, labelled 1.4.4
Now, I downloaded the Ubuntu source packages for both version and just did quick check if I could compile them. I could. However, I noticed that the source package of the new version does not contain dictionary files as they are published under LGPL and, hence, are removed during the "debianization".
Eventually, both version did not do the hyphenation. They even didn't allow me to choose a language for hyphenation rules. So, probably something went wrong, eh?
What I did, was quite stupid straighforward without digging much into how the code of Scribus is organized. This is why I'm not sure if my installation is simply missing some dependency or if it is really a problem of Scribus (I saw that some OverrideCursor methods were changed from 1.4.3 to 1.4.4) or of the Ubuntu packaging. If you have some hint for me I can look again.