Apparent magic number problem

[Colin J. Williams]

I have a program that I wish to run in both Python 2.7 and Python 3.2

The program runs correctly under each version, but it runs more slowly 
under 3.2.

This is probably due to the fact that the .pyc file is created for the 
Python 2.7 execution.

When Python 3.2 is run it fails to create a new .pyc file and if the 2.7 
.pyc is offered directly a magic number problem is reported.

Is there a bug here?  it seems to me that the Magic Number exception 
should lead to a new compile of the program.

Colin W.