Sounds that way to me too. The problem is what exactly is going on... More data:

mysql_config
Usage: /usr/local/mysql/bin/mysql_config [OPTIONS]
Options:
        --cflags         [-I/usr/local/mysql/include -Os -arch x86_64 
+-fno-common]
        --include        [-I/usr/local/mysql/include]
        --libs           [-L/usr/local/mysql/lib -lmysqlclient -lz -lm
+]
        --libs_r         [-L/usr/local/mysql/lib -lmysqlclient_r -lz -
+lm]
        --socket         [/tmp/mysql.sock]
        --port           [3306]
        --version        [5.0.51a]
        --libmysqld-libs [-L/usr/local/mysql/lib -lmysqld -lz -lm]
[download]

I'm noticing that /usr/local/mysql/lib does not have libm.* in it although it does have libz.a and libmysqlclient.(a|dylib).