I don't have time to investigate this right now, I do have access to a
10.5 server box though. With some luck I'll be able to create a patch
later today.
Looking at the code in urllib I found the most likely reason for the
problem: the Python script tries to resolve "CFStringCreateWithCString"
through the SystemConfiguration framework. It may well be that this
doesn't work on PPC systems and that this symbol should explicitly be
loaded from the CoreFoundation framework.
BTW. This probably also affects 3.x.