parse error before ntohl

hi!  i have been trying  to compile freetds on sco openserver 5.0.7, 
but  i have  the error:

/usr/include/sys/byteorder.h:47: parse error before `ntohl'

maybe i  missed  some #define on config.h or somehing else.

Please, could you help me?
the error details  are:


source='token.c' object='token.lo' libtool=yes \
DEPDIR=.deps depmode=gcc /bin/ksh ../../depcomp \
/bin/ksh ../../libtool --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. 
-I../../include  -I../../i
nclude -D_FREETDS_LIBRARY_SOURCE -D_REENTRANT -D_THREAD_SAFE -DDEBUG=1 
-Wall -Wstrict-prototypes -W
missing-prototypes -Wno-long-long  -g -O2 -c -o token.lo token.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../../include 
-I../../include -D_FREETDS_LIBRARY_SOURC
E -D_REENTRANT -D_THREAD_SAFE -DDEBUG=1 -Wall -Wstrict-prototypes 
-Wmissing-prototypes -Wno-long-lo
ng -g -O2 -c token.c -Wp,-MD,.deps/token.TPlo  -fPIC -DPIC -o libs/token.o
In file included from /usr/include/sys/netinet/in.h:39,
                  from /usr/include/netinet/in.h:18,
                  from ../../include/tds.h:31,
                  from token.c:42:
/usr/include/sys/byteorder.h:47: parse error before `ntohl'
/usr/include/sys/byteorder.h:47: warning: parameter names (without 
types) in function declaration
/usr/include/sys/byteorder.h:47: warning: parameter names (without 
types) in function declaration
/usr/include/sys/byteorder.h:47: warning: data definition has no type or 
storage class
/usr/include/sys/byteorder.h:48: parse error before `ntohs'
/usr/include/sys/byteorder.h:48: warning: parameter names (without 
types) in function declaration
/usr/include/sys/byteorder.h:48: warning: parameter names (without 
types) in function declaration
/usr/include/sys/byteorder.h:48: warning: data definition has no type or 
storage class
In file included from /usr/include/netinet/in.h:18,
                  from ../../include/tds.h:31,
                  from token.c:42:
/usr/include/sys/netinet/in.h:133: parse error before `u_long'
/usr/include/sys/netinet/in.h:133: warning: no semicolon at end of 
struct or union
/usr/include/sys/netinet/in.h:184: parse error before `u_short'
/usr/include/sys/netinet/in.h:184: warning: no semicolon at end of 
struct or union
/usr/include/sys/netinet/in.h:187: parse error before `}'
/usr/include/sys/netinet/in.h:234: field `imr_multiaddr' has incomplete type
/usr/include/sys/netinet/in.h:235: field `imr_interface' has incomplete type
/usr/include/sys/netinet/in.h:247: field `ip_dst' has incomplete type
In file included from /usr/include/sys/netinet/in_mp.h:29,
                  from /usr/include/sys/netinet/in.h:252,
                  from /usr/include/netinet/in.h:18,
                  from ../../include/tds.h:31,
                  from token.c:42:
/usr/include/sys/net/memory.h:42: parse error before `u_long'
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