If your firefox 3.5 has problems loading pages….

Being a long time user of firefox, I was excited seeing the new 3.5 come out, claiming its faster and all. However after upgrading, it seemed that from time to time pages would suddenly load as “server not found”, yet if I refresh once or twice the page will load properly again. After much investigation I believe I found the reason why it was doing this, for me at least, so if you have a similar problem give this fix a try:

First, open firefox and type about:config. This loads up the firefox configuration settings for more advanced purposes. Now right click somewhere on the screen where all the settings are, and click new, and boolean. For the name of this preference, type network.dns.disablePrefetch, and then set the value to TRUE. You should end up with a line in your settings looking like this:

click to enlarge

What this essentially does is disable a feature known as DNS prefetching introduced in firefox 3.5. In simple english what it does is obtain information before a user actually navigates to a page, in order to speed up browsing. Firefox 3 already had a similar function of prefetching, however because of the way this prefetching works (resolves and caches DNS lookups) it seems to cause problems for certain types of routers and computer setups.

Well after doing this, I haven’t encountered any server not found errors for healthy pages yet, so hopefully this will work for you too if you have a similar problem!