Calendar View: Font Size is "scrambled"

I have a customer that just recently has upgraded to the full client 8.0 and the calendar view is messed up:

Each entry is displayed with a lovely “Jelly Bean” format, but the text inside is messed up. The font size varies - even within the same word! This means that some text are displayed with font 8pt, some 10pt some 14pt and even 18pt size!! This makes text very hard to read and does not give the user any good look at the calendar entries…

When pressing ctrl+alt when opening the calendar gives them the old calendar ui back, but I see that only as a temporary solution. Any solution for this?