CPU usege too HIGH

[hugle]

In last past days, users confirmed of big lag in games..
I looged into the server, and saw big proccessor usage there:

last pid: 90449;  load averages:  5.55,  9.11,  6.74                                                 up 21+19:48:35  17:18:34
68 processes:  5 running, 63 sleeping
CPU states: 29.6% user,  0.0% nice, 34.6% system, 35.8% interrupt,  0.0% idle
Mem: 321M Active, 1313M Inact, 286M Wired, 85M Cache, 199M Buf, 3488K Free
Swap: 4079M Total, 216K Used, 4079M Free

  PID USERNAME PRI NICE  SIZE    RES STATE    TIME   WCPU    CPU COMMAND
46087 root      62   0  8912K  8624K RUN    393:39 28.86% 28.86% natd
63795 nobody    62   0   191M   190M RUN     22:38 22.61% 22.61% squid
87001 root      -6   0  9288K  8756K piperd   0:04  7.57%  7.57% perl
60589 root       2   0   672K   368K sbwait 297:12  0.24%  0.24% natd
65212 root      66  19 17416K 15684K RUN     89:50  0.00%  0.00% mlnet-real

perl# uptime
 5:24PM  up 21 days, 19:54, 2 users, load averages: 8.05, 11.78, 8.94

i have a little sciprt running avery 5 minutes.. it uses perl, but..

why natd is using so much resourses ?
there I have to dig the problem?
and why active memory is so low ?;/

-- 
Best regards,Hugle