error: libm.so.4 needed by libspeex may conflict w libm.so.5

[David Banning]

while attempting to build and install mplayer under FreeBSD Release 8.2 I get the error;

/usr/local/bin/ld: warning: libm.so.4, needed by /usr/local/lib/libspeex.so, may conflict with libm.so.5
/usr/local/lib/libgdk-x11-2.0.so: undefined reference to `XRRGetScreenResourcesCurrent'
/usr/local/lib/libgdk-x11-2.0.so: undefined reference to `XRRGetOutputPrimary'
collect2: ld returned 1 exit status
gmake: *** [mplayer] Error 1

If it's libspeex / libm.so.4 that is causing the error (thats what it looks like to me)
I wonder how to find out what libspeex is being used for - or for that matter what 
libm.so.4 is needed for.