Comment 14 for bug 814280

Inside the dmg you can also find a folder enblend-enfuse-4.0. These contain the enblend and enfuse version for Tiger. They are "simpler" ones without using the openmp options as Tiger doesn't support openmp.
Could you try these tiger versions on Lion. Read the Readme for instructions.

I'm wondering if something is going wrong in the openmp/multi-threading part of enblend.