Dynamic module importing with McMillan installer

[Sion Arrowsmith]

We have an application which we distribute as a .exe as created
with the McMillan installer, plus a suite of "plugins" which
can also be run as standalone applications for internal use.
The plugins work by freezing the standalone application and
taking the out1.pyz, suitably renamed, and adding the new file
name to sys.path at run time. We can then __import__ the module
(or, specifically, the plugin interface from it). Which works
fine, apart from one new plugin which works unfrozen, works as
a frozen standalone, but when trying to import it frozen
generates an ImportError from Installer/iu.py, "No module named
<name>". It's using, as far as I can tell, the same commands to
build the .pyz as a correctly functioning plugin module. Does
anyone have the slightest clue what might be going wrong?
(Python 2.3 on W2K, McMillan Installer 5 b5_5.)

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