squid collapse

[zey]

I installed squid on my network gateway which is ubuntu jaunty.
Recently after I changed my connection on my ISP from static IP address to dynamic IP address squid getting collapse frequently.

The error : unable to determine IP adress ... bla bla bla..

I checked for DNS and i'm sure no wrong configuration.
Why this is happen after I user dynamic IP address?
This error never happen when I use static IP.

Hope you can help me.
thanks