ImportError question

[mary]

I'm trying to build and use GDChart on AIX. It seems to have built ok, but
on trying to import the shared library, I get the following error message
even though the gdchart.so file exists in the current directory. I've tried
adding to PYTHONPATH, but that makes no difference. What does this
error *really* mean? (Also, can I get more information somehow?):

python test.py
Traceback (most recent call last):
  File "test.py", line 15, in ?
    import gdchart
ImportError: from module gdchart.so No such file or directory