[Gdal-dev] gdal_merge.py Python config problem?

[Andrew Williams]

I'm quite familiar with GDAL executables, but I'm having trouble with Python.
 
I managed to actually get two images to merge correctly once. However I was called to another task and something has happened in the mean time and I cannot repeat the success,
 
I've learn't quite a bit about Python, but I must be missing something. I've configured environment variables and made sure all files required are available but I still get the error below.
 
It refers to the _gdal.dll. This file is available in all paths and is the same one that must have previously worked. Am I missing something in my Pythonwin configuration?
 
gdal.AllRegister()
AttributeError: 'module' object has no attribute 'AllRegister'