Vorbis - Dec 2005 - inking encoder and decoder into project

I am building a managed assembly in Visual Studio.Net 2003 that can encode
and decode ogg vorbis files. I currently have it decoding files fine,
however when I link in vorbisenc.lib I get a bunch of errors saying that
certain symbols are already defined in vorbis.lib.
How do I link in the libraries

vorbisenc.lib (for encoding)
vorbis.lib (for decoding)
ogg.lib

without the symbols in vorbisenc.lib conflicting with symbols in vorbis.lib?

Thanks very much!