2.0b4 compile issue's on FreeBSD4.8. - 1.2 compiles fine

am having difficulty compiling Nagios 2.0b4 on FreeBSD4.8
Example of what happens as follows:-

The configure runs fine…
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sudo ./configure --with-gd-lib=/usr/local/lib --with-gd-inc=/usr/local/include
.
.
*** Configuration summary for nagios 2.0b4 08-02-2005 ***:

General Options:

    Nagios executable:  nagios
    Nagios user/group:  nagios,nagios
   Command user/group:  nagios,nagios
        Embedded Perl:  no
         Event Broker:  yes
    Install ${prefix}:  /usr/local/nagios
            Lock file:  ${prefix}/var/nagios.lock
       Init directory:  /usr/local/etc/rc.d
              Host OS:  freebsd4.8

.
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The Compile fails as follows:-
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sudo make all
cd ./base && make
gcc -g -O2 -I/usr/local/include -DHAVE_CONFIG_H -DNSCORE -c broker.c
In file included from …/include/config.h:174,
from broker.c:26:
/usr/include/sys/wait.h:62: warning: WIFEXITED' redefined ../include/config.h:102: warning: this is the location of the previous definition /usr/include/sys/wait.h:63: warning:WEXITSTATUS’ redefined
…/include/config.h:99: warning: this is the location of the previous definition
In file included from …/include/config.h:114,
from broker.c:26:
/usr/include/sys/resource.h:58: field ru_utime' has incomplete type /usr/include/sys/resource.h:59: fieldru_stime’ has incomplete type
/usr/include/sys/resource.h:119: syntax error before int32_t' /usr/include/sys/resource.h:124: syntax error beforerlim_t’
/usr/include/sys/resource.h:130: syntax error before `fixpt_t’
*** Error code 1

Stop in /home/staff/noc/mckay/ports/Nagios-2/nagios-2.0b4/base.
*** Error code 1
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Nagios 1.2 compiles no problem at all on the same box! Has anyone seen this before or can you provide any idea solutions to get 2.0b4 compiling on FreeBSD4.8.

Many Thanks