makefile.unix upnp ifdef doesn't seem to be working as intended unless I got an issue with my make (3.81).

tar xfz tarballs/bitcoin-0.3.21rc-linux.tar.gz
cd bitcoin-0.3.21/src
make -f makefile.unix bitcoind
g++ -c -O2 -Wno-invalid-offsetof -Wformat -g -D__WXDEBUG__ -DNOPCH -DFOURWAYSSE2 -DUSE_SSL -DUSE_UPNP=0 -o obj/nogui/util.o util.cpp

I use instead in makefile.unix

ifeq ($(USE_UPNP),1)
  LIBS += -l miniupnpc
  DEFS += -DUSE_UPNP
endif

It looks like it may need to be changed in makefile.*

I'm sorry but I don't know git yet so I could not fix myself. Learning git just moved up on my priority list though.

uname -a
Linux bc0 2.6.35-22-generic #33-Ubuntu SMP Sun Sep 19 20:32:27 UTC 2010 x86_64 GNU/Linux
make -v
GNU Make 3.81