[CentOS] postfix startup issue - CentOS 5.2

Hi

I am trying to get postfix going on a friends VPS however after 
installing on startup i see this

Jan 27 11:15:13 postfix/postfix-script: starting the Postfix mail system
Jan 27 11:15:13 postfix/master[28090]: fatal: pipe: Cannot allocate memory

and a top gives

Tasks:  23 total,   1 running,  22 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  
0.0%st
Mem:    524288k total,   160920k used,   363368k free,        0k buffers
Swap:        0k total,        0k used,        0k free,        0k cached

any clue?

thanks

# uname -i
Linux 2.6.18-028stab059.6 #1 SMP Fri Nov 14 14:01:22 MSK 2008 i686 i686 
i386 GNU/Linux

# cat /etc/redhat-release
CentOS release 5.2 (Final)