My server crash please help

[mrmagoo]

My server is crashing and I cant figure out why, Its running Ubuntu server 6.10 And ISP Config 2.2.15 I installed following the perfect ubuntu setup inst.
I take a look at the logs but the only thing that is strange to me is this:
Sep 12 19:19:26 globamarket authdaemond: PAM unable to dlopen(/lib/security/pam_foreground.so)
Sep 12 19:19:26 globamarket authdaemond: PAM [dlerror: /lib/security/pam_foreground.so: undefined symbol: pam_set_data]
Sep 12 19:19:26 globamarket authdaemond: PAM adding faulty module: /lib/security/pam_foreground.so
at syslog, userlog. I need to know where and what can i do to identify my problem in order to solve it
This is the lines from syslog when ubuntu reboot:
Sep 10 23:53:58 globamarket postfix/smtpd[17908]: disconnect from unknown[58.186.90.99]
Sep 11 14:22:41 globamarket syslogd 1.4.1#18ubuntu6: restart.
Every time is the same
Thanks

[falko]

What are the outputs of df -h and dmesg?

[mrmagoo]

The outputs

[falko]

[42949573.200000] Out of Memory: Kill process 4607 (memtest) score 45014 and children.
[42949573.200000] Out of memory: Killed process 4607 (memtest).
[42949579.040000] oom-killer: gfp_mask=0x200d2, order=0
[42949579.040000] <c014e2a2> out_of_memory+0x132/0x160 <c01501f3> __alloc_pages+0x2e3/0x300
[42949579.040000] <c015fa91> read_swap_cache_async+0x81/0xb0 <c01565a6> swapin_readahead+0x56/0x70
[42949579.040000] <c01580ff> __handle_mm_fault+0x58f/0xbc0 <c01261ed> getnstimeofday+0xd/0x30
[42949579.040000] <c0137f5f> hrtimer_start+0x9f/0xf0 <c02da384> do_page_fault+0x3b4/0x7a0
[42949579.040000] <c02d9fd0> do_page_fault+0x0/0x7a0 <c0103b73> error_code+0x4f/0x54Seems to be a problem with your memory. How much RAM do you use?

Please use memtest ( http://www.memtest.org/ ) to check if your memory is ok.