Bolding issue titles in the list is a way to see whether someone has responded to a support issue
These are the "rules" for "bold titles":
An issue get "bold title" if one of the following happens:
* A new issue is created by a Support User.
* A new comment from a Support User on an issue.
* A new mail is received on an issue, sent by a Support User.
The "bold title" is removed if one of the following happens:
* A normal user opens the issue (i.e. opens it and takes a look at it)
* A normal user makes an "Email reply" on the issue.
* The issue Status is changed to a "Closed"-status
* A comment is made on the issue, from the "context menu"