[PyQt] failed build on Mac 10.5

[Mitchell Model]

I got a new Mac Desktop Pro at work and am trying to reproduce the  
environment I was using on my MacBook Pro. I am using 10.5 on each  
because the pieces aren't ready for 10.6. A couple of months ago I  
successfully installed Qt and Python 2.6 on my MacBook Pro, and was  
able to download, configure, compile, and install PyQt. When I try to  
do all this on my new machine I get the following error:

	Undefined symbols:
	  "_PyString_FromString", referenced from:
	      PyCustomWidgets::PyCustomWidgets(QObject*)in pluginloader.o
	ld: symbol(s) not found
	collect2: ld returned 1 exit status
	make[1]: *** [libpythonplugin.dylib] Error 1
	make: *** [all] Error 2

I gave no arguments to either the sip or PyQt configure.py when I ran  
it.

This is a pretty clean installation of 10.5. I have installed Python  
2.6 using its installer and Qt 4.5 using its installer.

The same thing happens if I use 10.5's Python 2.5.

However, I am able to successfully download the Python 3.1 source,  
build that then use python3 to configure sip and PyQt.

I am delighted that PyQt works with Python 3.1, but does anyone know  
why my builds fail when I configure with Python 2.5 or 2.6?