[CEGUI 7.9]Unreadable text with small windows

[Neckara]

Hello

I use CEGUI 7.9 and CEGUI Layout Editor and I have a "text area" into a small Irrlicht Window.
The text are is resized according to the Irrlicht Window's size but the text's text area too so it becoming unreadable even if I use 0 for scale and the window's dimension for offset.

How can I solve this problem ?

Thanks for reading,