Resource temporarily unavailable

Hi everyone

From time to time i get the following error:
could not fork new process for connection: Resource temporarily unavailable

im using Postgres 7.4.5, with kernel 2.6.2

my conf is:

max_connections = 400

and system is:

www3:/etc/postgresql# ulimit -a
core file size        (blocks, -c) 0
data seg size         (kbytes, -d) unlimited
file size             (blocks, -f) unlimited
max locked memory     (kbytes, -l) unlimited
max memory size       (kbytes, -m) unlimited
open files                    (-n) 1024
pipe size          (512 bytes, -p) 8
stack size            (kbytes, -s) 8192
cpu time             (seconds, -t) unlimited
max user processes            (-u) 256
virtual memory        (kbytes, -v) unlimited

im totaly bogus, any ideas ?

Thanks
--------------------------
Canaan Surfing Ltd.
Internet Service Providers
Ben-Nes Michael - Manager
Tel: 972-4-6991122
Fax: 972-4-6990098
http://www.canaan.net.il
--------------------------