Using IE I have no problems but Using Firefox all

Using IE I have no problems but Using Firefox all searches result in ERROR
The requested URL could not be retrieved

While trying to retrieve the URL: http://uk.search.yahoo.com/

The following error was encountered:

* Unable to forward this request at this time.

This request could not be forwarded to the origin server or to any parent caches. The most likely cause for this error is that:

* The cache administrator does not allow this cache to make direct connections to origin servers, and
* All configured parent caches are currently unreachable.

Your cache administrator is webmaster.
Generated Fri, 18 Sep 2009 18:13:00 GMT by lithium.onspeed.com (squid/2.7.STABLE5)