error compiling stl samples with g++ in cygwin

[TheOne]

I downloaded sample codes from 
http://www.cs.rpi.edu/~musser/stl-book/source/src.zip
and tried to compile them.

I started my cygwin on xp, renamed Makefile.unix to Makefile and typed
"make". After several successful compilation, it spat out following
error :

/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libcygwin.a(libcmain.o):
(.text+0xab): undefined reference to `_WinMain@16'
collect2: ld returned 1 exit status
make: *** [ex04-01] 오류 1

There's no WinMain in the code. Strangely, when I retried "make",
compile is succuessful for the file but again after several succuess,
make complain with the same error message with another source code.

What can cause the problem?

TIA.