decode(..., errors='ignore') has no effect

[Jens Müller]

Hi,

I try to decode a string,e.g.
u'M\xfcnchen, pronounced [\u02c8m\u028fn\xe7\u0259n]'.decode('cp1252', 
'ignore')
but even thoug I use errors='ignore'
I get UnicodeEncodeError: 'charmap' codec can't encode character u'\u02c8' 
in position 21: character maps to <undefined>

How come?

Thanks,
Jens