Problem with Writer Form and Greek chars


I have created a Form (a request form delivered as PDF to my customers) with Writer containing several types of controls (Textboxes, Formatted Fields, List Boxes etc.) and I have exported that as PDF.

The problem I have is that when I fill (through PDF) the TEXTBOXES or FORMATTED FIELDS with GREEK CHARACTERS (e.g. ΚΑΛΗΜΕΡΑ, ΚΑΛΗΣΠΕΡΑ, ΓΕΙΑ ΣΟΥ… ) and after I select something from a LISTBOX or make a selection from OPTION BUTTON or CHECK BOX the TEXTBOX or FORMATTED FIELD with the GREEK text becomes NON VISIBLE

Be careful!!! NOT EMPTY but looks like the font color becomes WHITE (if someone selects the content of this field can see that)

If TEXTBOX content is in English NO PROBLEM