could not send data to client: Broken pipe

Hi,

I'm using Postgres 7.4. I have a web application built with php4 using postgres7.4

I was going through /var/log/messages of my linux box ( SLES 9). I encountered the following messages quite a few times.

>postgres[20199]: [4-1] ERROR:  could not send data to client: Broken pipe
>postgres[30391]: [6-1] LOG:  could not send data to client: Broken pipe
>postgres[30570]: [6-1] LOG:  could not send data to client: Broken pipe

Can anyone help me in interpreting these messages?
What is causing this error msg? What is the severity?


Regards

-- Pradeep