Slow Firefox on Vista with Visual Studio Cassini Webserver

Had a problem come up today while trying to connect to cassini webserver with visual studio.  Firefox was acting really slow when browsing.  Turns out, I wasn’t the only one experiencing the problem.  (Thank goodness).

Here is the fix:

It turns out that the slowness is caused by an IPv6 issue with DNS and can easily be resolved by turning IPv6 support off in Firefox while doing localhost testing. To make the change, type about:config in the address bar, locate the network.dns.disableIPv6 setting and double-click on it to set it to true. This does the trick for the Firefox localhost issue on Vista and everything is running fast again.

Thanks Andreas Kraus and Dan Wahlin.