Update: As pointed out by Roy in the comments below, Microsoft has released an update to the MS12-078/KB 2753842, and initial indications are that this is solving the problems. You can get that updated update through the normal Windows Update.

A recently release Windows update from Microsoft had a side impact on multiple software applications, including various versions of CorelDRAW and Corel Painter, as well as software from other software vendors. In CorelDRAW, the effect of this update has been for certain fonts to dissapear in your .CDR documents. The specific Microsoft update is MS12-078/KB 2753842. Corel is working closely with Microsoft to get this problem resolved as quickly as possible. The only work-around until a final solution has been released is to uninstall the update from your system, which is not ideal as this update was released to address a security concern. Be sure to "hide" the update once uninstalled or to configure for Windows to ask which updates to install because windows update will try to re-install it again automatically otherwize.

For more detailed information on the issue, you can read following thread on CorelDRAW.com and on the Microsoft Community site. 

As mentioned previously, Corel is working with Microsoft to resolve this issue as quickly as possible.