Hi Enrico,<br><br>I'll try to explain in more detail:<br><br>What happens is:<br>Geany presumably keeps the main window vertical coordinates of the functions, methods, classes, etc. (so that when you click on a function name in the side-bar, the main window scrolls to  this function). When you change the font size, the total size of the main window changes too, and those coordinates are no longer correct. 
<br><br><br>Hi,<br><br>&gt; I have just noticed that changing the font size breaks the<br>&gt; synchronisation between main source window and the sidebar with<br>&gt; function names.<br>I don't know what you mean. Can you explain it in more detail, perhaps
<br>with a screenshot?<br>Thanks.<br><br><br>Regards,<br>Enrico<br>