that Debian Squeeze says:
gstreamer-0.10 development files not found, gstreamer support disabled
So I guess you need libgstreamer-plugins-base0.10-dev.
Detlef has sent a patch that wasn't applied however:
http://www.winehq.org/pipermail/wine-patches/2010-November/096133.html
Thanks Paul and others! "libgstreamer-plugins-base0.10-dev" was exactly that package which fixed the issue.
W.