So, I am responding to my own post. If you have OS version version 18.104.22.168 (platform 22.214.171.124) kernel v. 126.96.36.199 like I did, you should also have this caller id font bug.
The solution is to upgrade your OS. Follow this link to another post on this forum: http://www.blackberryforums.com/viewtopic.php?t=1652
Note that the OS upgrade is to 188.8.131.52, not .142. It is a must-do, however, since it also fixes the speakerphone bug and possibly others. Read the whole thread before installing.