Fonts bug - restores to arial

Hello,
I take advantage of this discussion to introduce another problem I have concerning fonts.
First of all, to be honest I have to say that also in GS 6 I had many troubles with text formatting, it is GS’s weak point from my point of view. I noticed this matters:

  1. exactly what Mr_Sandman says

  2. when I paste a text from another phrase (so not from internet or another page with different formatting) it is light grey although it was black before

  3. this is the strangest thing, finally I discovered the matter. I have this kind of paragraphs:

DESCRIZIONE: lorem ipsum bla bla…

FORMATO: lorem ipsum bla bla…

CONSERVAZIONE: lorem ipsum bla bla…

Then, I delete “lorem ipsum bla bla…” and I start writing another phrase. Almost every time I write a word with ’ (apostrophe) the first bold word automatically becomes normal (without bold). It is quite annoying since it is the same every time I write a word like " all’angolo " or " can’t ". I made a screenshot to explain it:

Thank you for any help