This is because you have tried to download the Testing version. You see javispedro? I already knew that,the fix to this problem will hurt! The user will need to enable the Devel Repos,download libavcodec52(Don't forget to update your apt-get first).Next, the user will need to disable the Devel repos and enable the Testing repos(Update apt-get again).Download the libavcodec52 again.If you are lucky,you won't face the"Missing dependencies" problem.
Preenv should initialize the library properly.It fails to do it at most.