SQUID Problem

Hi All,
I am working on RH 8 and have configured the squid proxy server version squid-2.3.STABLE4-10.i386. It is working properly & I have checked a no of permissions like access time for certain ips to access internet, blocking sites etc etc.
But I am having a problem like suddenly after some time i gert an error like the below.
I am attaching the logs in the zip file
I am not able to get through the problem. Can anybody help me please.
Waiting for your helpful reply.....

Bye,
Sahas


The requested URL could not be retrieved

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While trying to retrieve the URL: URL

The following error was encountered:

Unable to determine IP address from host name for URL
The dnsserver returned:

No DNS records
This means that:

The cache was not able to resolve the hostname presented in the URL.
Check if the address is correct.

Your cache administrator is URL.



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Generated Fri, 30 May 2003 11:50:09 GMT by URL (Squid/2.3.STABLE4)