The problems may not be unrelated.
Permissions can be a problem with such symptoms.
I once solved a similar problem by opening the Premiere project before opening Encore, so I would try that. But not likely to help.
Try options in the following link, particularly related to permissions. Thais is the most recentl troubleshooting guide I know of.
Troubleshoot system errors and freezes | Adobe software on Mac OS 10.x
http://kb2.adobe.com/cps/824/cpsid_82414.html
As troubleshooting, open Encore, create a new project, DL to a PR sequence (make something short, so there is no delay for that reason). If that works, it is more likely related to your project (PR or EN) rather than a basic Encore/DL problem.