Error when launch nosetest:

ERROR: Failure: ImportError (DLL load failed: %1 is not a valid Win32 application.)

Traceback (most recent call last):
File "C:\Python27\lib\site-packages\nose\loader.py", line 418, in loadTestsFromName
addr.filename, addr.module)
File "C:\Python27\lib\site-packages\nose\importer.py", line 47, in importFromPath
return self.importFromDir(dir_path, fqname)
File "C:\Python27\lib\site-packages\nose\importer.py", line 94, in importFromDir
mod = load_module(part_fqname, fh, filename, desc)
File "C:\projects\avtranscoder\test\pyTest\testTranscoderTranscodeAudioWave.py", line 10, in
from pyAvTranscoder import avtranscoder as av
File "C:\projects\avtranscoder\build\lib\python2.7\site-packages\pyAvTranscoder\avtranscoder.py", line 32, in
_avtranscoder = swig_import_helper()
File "C:\projects\avtranscoder\build\lib\python2.7\site-packages\pyAvTranscoder\avtranscoder.py", line 28, in swig_import_helper
_mod = imp.load_module('_avtranscoder', fp, pathname, description)
ImportError: DLL load failed: %1 is not a valid Win32 application.