>  Should this 'undesirable' behavior be documented? My thoughts are

Document should definitely reflect the code whether the behaviour is
desirable or not.

>  a) All the key,value pairs in the named section be retrived from entire
>  file. Just appending the dict.

Isn't this what is happening now unless I am not following you?

>  Otherwise,
>  b) An Exception can be thrown if it encounters an invalid Configfile
>  having multiple same sections which can cause problem, but I cannot
>  readily think of one such case.

I have no problem with throwing an exception in case of duplicate
sections but I don't think that can be done by default (it may break
some programs).