With the options "noapic" and "notsc" plus ntp-server the clock remains sync but with high cpu usage... look this:

  JOBID PARTITION     NAME     USER  ST       TIME  NODES NODELIST(REASON)
    361       pnc Bet7_pon      pnc   R    1:08:07      4 teoria,teoria[1-3]
    360    testes teste1MA  rodrigo   R    1:59:50      2 teoria[5,8]
teoria9: Qui Jan 24 21:36:54 BRT 2008
teoria1: Qui Jan 24 21:36:54 BRT 2008
teoria2: Qui Jan 24 21:36:54 BRT 2008
teoria5: Qui Jan 24 21:36:54 BRT 2008
teoria3: Qui Jan 24 21:36:54 BRT 2008
teoria7: Qui Jan 24 21:36:54 BRT 2008
teoria4: Qui Jan 24 21:36:54 BRT 2008

-> teoria8: Qui Jan 24 20:26:36 BRT 2008 <-

teoria10: Qui Jan 24 21:36:55 BRT 2008
teoria6: Qui Jan 24 21:36:55 BRT 2008

After 2:00 hs the teoria8's clock delayed 1:10 hs!

rodrigo@teoria8:~$ ps aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0   4020   864 ?        Ss   10:00   0:00 /sbin/init
root         2  0.0  0.0      0     0 ?        S<   10:00   0:00 [kthreadd]
root         3  0.0  0.0      0     0 ?        S<   10:00   0:00 [migration/0]
root         4  0.0  0.0      0     0 ?        S<   10:00   0:00 [ksoftirqd/0]
root         5  0.0  0.0      0     0 ?        S<   10:00   0:00 [watchdog/0]
root         6  0.0  0.0      0     0 ?        S<   10:00   0:00 [migration/1]
root         7  0.0  0.0      0     0 ?        S<   10:00   0:00 [ksoftirqd/1]
root         8  0.0  0.0      0     0 ?        S<   10:00   0:00 [watchdog/1]
root         9  0.0  0.0      0     0 ?        S<   10:00   0:00 [events/0]
root        10  0.0  0.0      0     0 ?        S<   10:00   0:00 [events/1]
root        11  0.0  0.0      0     0 ?        S<   10:00   0:00 [khelper]
root        45  0.0  0.0      0     0 ?        S<   10:00   0:00 [kblockd/0]
root        46  0.0  0.0      0     0 ?        S<   10:00   0:00 [kblockd/1]
root        49  0.0  0.0      0     0 ?        S<   10:00   0:00 [kacpid]
root        50  0.0  0.0      0     0 ?        S<   10:00   0:00 [kacpi_notify]
root       184  0.0  0.0      0     0 ?        S<   10:00   0:00 [kseriod]
root       233  0.0  0.0      0     0 ?        S    10:00   0:00 [pdflush]
root       234  0.0  0.0      0     0 ?        S    10:00   0:00 [pdflush]
root       235  0.0  0.0      0     0 ?        S<   10:00   0:00 [kswapd0]
root       279  0.0  0.0      0     0 ?        S<   10:00   0:00 [aio/0]
root       280  0.0  0.0      0     0 ?        S<   10:00   0:00 [aio/1]
root      1491  0.0  0.0      0     0 ?        S<   10:00   0:00 [ksuspend_usbd]
root      1494  0.0  0.0      0     0 ?        S<   10:00   0:00 [khubd]
root      1512  0.0  0.0      0     0 ?        S<   10:00   0:00 [ata/0]
root      1515  0.0  0.0      0     0 ?        S<   10:00   0:00 [ata/1]
root      1518  0.0  0.0      0     0 ?        S<   10:00   0:00 [ata_aux]
root      1587  0.0  0.0      0     0 ?        S<   10:00   0:00 [khpsbpkt]
root      1863  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_0]
root      1864  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_1]
root      2324  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_2]
root      2325  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_3]
root      2347  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_4]
root      2348  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_5]
root      2404  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_6]
root      2405  0.0  0.0      0     0 ?        S<   10:00   0:00 [scsi_eh_7]
root      2544  0.0  0.0      0     0 ?        S<   10:00   0:00 [knodemgrd_0]
root      2722  0.0  0.0      0     0 ?        S<   10:00   0:00 [kjournald]
root      2876  0.0  0.0  19168   960 ?        S<s  10:00   0:01 /sbin/udevd --daemon
root      3410  0.0  0.0      0     0 ?        S<   10:00   0:00 [kpsmoused]
daemon    3768  0.0  0.0   8084   576 ?        S<s  10:00   0:00 /sbin/portmap
root      4016  0.0  0.0      0     0 ?        S<   10:00   0:00 [rtl8187]
statd     4201  0.0  0.0  10208   800 ?        S<s  10:01   0:00 /sbin/rpc.statd
root      4277  0.0  0.0      0     0 ?        S<   10:01   0:00 [rpciod/0]
root      4278  0.0  0.0      0     0 ?        S<   10:01   0:00 [rpciod/1]
root      4318  0.0  0.0      0     0 ?        S    10:01   0:00 [lockd]
root      4451  0.0  0.0      0     0 ?        S<   10:01   0:00 [kjournald]
root      4767  0.0  0.0   3864   588 tty4     Ss+  10:01   0:00 /sbin/getty 38400 tty4
root      4768  0.0  0.0   3864   588 tty5     Ss+  10:01   0:00 /sbin/getty 38400 tty5
root      4770  0.0  0.0   3864   588 tty2     Ss+  10:01   0:00 /sbin/getty 38400 tty2
root      4773  0.0  0.0   3864   588 tty3     Ss+  10:01   0:00 /sbin/getty 38400 tty3
root      4774  0.0  0.0   3864   592 tty1     Ss+  10:01   0:00 /sbin/getty 38400 tty1
root      4775  0.0  0.0   3864   588 tty6     Ss+  10:01   0:00 /sbin/getty 38400 tty6
syslog    4817  0.0  0.0  12296   780 ?        Ss   10:01   0:00 /sbin/syslogd -u syslog
root      4837  0.0  0.0   8120   584 ?        S    10:01   0:00 /bin/dd bs 1 if /proc/kmsg of /var/run/klogd/kmsg
klog      4840  0.0  0.0   6408  3100 ?        Ss   10:01   0:00 /sbin/klogd -P /var/run/klogd/kmsg
root      4859  0.0  0.0  48908  1180 ?        Ss   10:01   0:00 /usr/sbin/sshd
root      4902  0.0  0.0  55396  1356 ?        Sl   10:01   0:00 /usr/sbin/ypbind
root      4921  0.0  0.0  32880   744 ?        Ssl  10:01   0:0 [glusterfsd]                                                                     
ntp       4958  0.0  0.0  19156  1288 ?        Ss   10:01   0:00 /usr/sbin/ntpd -p /var/run/ntpd.pid -u 105:111 -g
daemon    4973  0.0  0.0  16432   428 ?        Ss   10:01   0:00 /usr/sbin/atd
root      4984  0.0  0.0  20944   860 ?        Ss   10:01   0:00 /usr/sbin/cron
root      5003  0.0  0.0  33200  2048 ?        S    10:01   0:00 /usr/local/sbin/slurmd
root      8071  0.0  0.0  63892  2820 ?        Ss   20:08   0:00 sshd: rodrigo [priv]
rodrigo   8074  0.0  0.0  64240  1760 ?        S    20:08   0:00 sshd: rodrigo@notty
rodrigo   8076  166 14.4 3260880 585472 ?      Rsl  20:08  29:39 /programas/g03/linda-exe/l914.exel 402653184 BetF7_ponte_com_1N.chk 1 /scratch/Ga
root      8161  0.0  0.0  63892  2856 ?        Ss   20:26   0:00 sshd: rodrigo [priv]
rodrigo   8163  0.0  0.0  64240  1800 ?        S    20:26   0:00 sshd: rodrigo@pts/0
rodrigo   8164  0.0  0.0  19376  2312 pts/0    Ss   20:26   0:00 -bash
rodrigo   8166  0.0  0.0  15064  1148 pts/0    R+   20:26   0:00 ps aux

Ubuntu 7.10 functions perfectly.