There is a big problem with twisted on Fedora/Redhat multiarch. For example, x86_64. The problem is that Fedora puts arch-independent (.py) code into a different directory than arch-dependent code. Unfortunately, this doesn't quite work correctly with python's module search algorithm. The problem shows up when twisted-sumo is installed. Then we have: /usr/lib/python2.4/site-packages/twisted/... and /usr/lib64/python2.4/site-packages/twisted/... This won't work. I realize the problem is with python module search, but it looks like a big effort fix the code. A simpler solution would be for twisted to just avoid the problem. If twisted put core c-code into a different place, we could have: /usr/lib64/python2.4/site-packages/twisted-core That would solve the problem.