emacs python mode suddenly doesn't like shebang symlinks

[Ivan Uemlianin <iau@ukfsn.org>]

Dear all

Any ideas on a suddenly misbehaving package?

My emacs python mode (debian package python-elisp) has suddenly 
developed a fault.

My python scripts start with the shebang line:

 #! /usr/bin/python

On my system /usr/bin/python is a symlink to python2.3 (I also have 
python2.2).

With that shebang in the script, the emacs command py-execute-buffer 
gives an error message 'Wrong type argument: sequencep, cpython'. 
Remove the shebang line, or point the shebang to python2.3 or 2.2 
instead of the symlink, and  py-execute-buffer works fine.  But it seems 
not to like the symlink.

Everything was fine until yesterday.  What happened?  I installed 
debian-junior stuff (for my son, honest), and I can only think that 
overwrote something I shoundn't have.

Any ideas on what might have gone wrong and how I can fix it?

Best wishes

Ivan