iTapTap

Here comes the new version.After a lot of testing on Tiger it seems that Tiger has a very different Dictionary.This means as for now the Language Pack is for Leopard only.Download Link 
ChangeLog
v.1.2
-Fixed Dictionaries format.
-Removed Tiger compatibility
-Start Dictionary.App after Install 
v.1.1
-Added Tiger support for Testing Purpose-Distributed via compressed DMG image file for smaller size

Tested on Leopard - fully working.

This will install two more Dictionary to your Dictionary.App

-  Bulgarian - English

-  English - Bulgarian

You can download it here