it was discussed here back when I did it. I think first it was wrong python version, then it was mainly wrong glibc version linked against the swig stuff vs. the version on my ubuntu. I ended up using a version of cppForSwig I compiled on a different host. Read post
https://bitcointalk.org/index.php?topic=56424.msg965679#msg965679 and onwards for more info.
Ahh. All that python dependency stuff should be a non-issue, now. And it wouldn't have been issue if you were using Ubuntu 10.04-32bit (which is what I made the offline-bundle for), but I recognize some users will use different distros and/or want to compile it themselves. However, even that has been improved with static compiling of python into the C++ utilities.
When I do the next release, I'll make a couple extra offline bundles -- one for 10.04 and 12.04. And I will include all the packages you need to compile it, not just install it.