I am installing Mint 15 64bit Cinnamon edition on my friend's computer.
There is a strange font issue in KDE applications. In number fields of application settings it looks like some strange font is used. It is a bit hard to explain, so please have a look at these screenshots.
and here non-KDE app to show that GTK has no such issue
I have checked KDE font settings, Cinnamon font settings, I tried to remove every link from /etc/fonts/conf.d and nothing worked.
EDIT: I have reinstalled Mint 15 Cinnamon on the same machine and the problem is present also in vanilla installation. I just added Clementine to vanilla Mint 15 and it has the issue.