wxmsw26u_vc_enthought.dll not found ?

hello,

I've a application, based on wxPython en SciPy.
When I run the application in an IDE, everything works perfect without any error messages
(about 1 out of 100 cases the error described below will happen in IDE too).

When I run the application standalone, I get the following error message

and when I press OK, the program continues and works perfect.

Now I've searched for the string "wxmsw26u_vc_enthought.dll",
but I can't find it anywhere ??

How can I prevent this error message ?
Any other hints for finding the problem would also be appreciated.

I run on winXP, SP2,
Python 2.4.3 - Enthought Edition 1.1.0 (#69, Oct 6 2006, 12:53:45) [MSC v.1310 32 bit (Intel)] on win32.
and updated wxPython to version 2.8.

thanks,
Stef Mientki