User-Agent: w3m/0.3 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.6) Gecko/20040113 Occaisionally after a DNS timeout, the browser will fail to resolve any further DNS queries. Web pages on hosts that were previously resolved still display without issue. The hosts that will not resolve in Mozilla resolve without issue from the command line on the same machine. This usually occurs in long-running browser sessions (circa three weeks), but can occur in as little as five minutes of browsing. It always happens eventually. This issue has been present since at least version 1.2, though possibly also earlier versions. The only work around I've found is to close down the browser and restart it, after which DNS usually works without issue. Reproducible: Always Steps to Reproduce: 1. Leave browser open continuously for a long period of time. 2. Visit a web page with a hostname that is not in cache. Actual Results: Mozilla fails to resolve the hostname. Mozilla continues to fail to resolve any hostname not in cache until it is shut down. Expected Results: Host names should have resolved correctly.

can you reproduce this with 1.7b or current nightly build ?

I was seeing this, but with a recent nightly build, it is fixed. Mozilla 1.7 RC1 should have the fix. *** This bug has been marked as a duplicate of 240759 ***

I won't change the resolution of the bug, but this may be neither a duplicate nor a Mozilla bug. Windows is reported to cache unsuccessful lookup attempts and fail to look again until the cache has expired, in 5 minutes or so. See http://kb.mozillazine.org/Error_loading_websites#DNS .