[Pkg-alsa-devel] Bug#451266: apt-pinning

[Alter Ego]

I'm running a pure Lenny version.

I have read that installing packages from other branches can cause 
problems, such as quite a large amount of packages that need to be 
upgraded or existing packages being unistalled due to unsatisfieable 
dependencies...

This system came from etch and, in the future, I want it to upgrade to 
next testing without any problems :)

So, the question is:

Can I do the apt-pinning you are recommending without damaging my system 
or running into broken/insatisfieable dependencies?

JJCale