Either Privoxy is not running, or your browser is configured for a different port than what Privoxy is using.
The old Privoxy (and also Junkbuster) used port 8000 by default. This has been changed to port 8118 now, due to a conflict with NAS (Network Audio Service), which uses port 8000. If you haven't, you need to change your browser to the new port number, or alternately change the listen-address option in Privoxy's main configuration file.
If the ad had been displayed before you added its URL, it will probably be held in the browser's cache for some time, so it will be displayed without the need for any request to the server, and Privoxy will not be in the picture. The best thing to do is try flushing the browser's caches. And then try again.
If this doesn't help, you probably have an error in the rule you applied. Try pasting the full URL of the offending ad into http://config.privoxy.org/show-url-info and see if it really matches your new rule.
First verify that it is indeed a Privoxy problem, by toggling off Privoxy through http://config.privoxy.org/toggle, and then shift-reloading the problem page (i.e. holding down the shift key while clicking reload. Alternatively, flush your browser's disk and memory caches).
If still a problem, go to http://config.privoxy.org/show-url-info and paste the full URL of the page in question into the prompt. See which actions are being applied to the URL, and which matches in which actions files are responsible for that. Now, armed with this information, go to http://config.privoxy.org/show-status and select the appropriate actions files for editing.
You can now either look for a section which disables the actions that you suspect to cause the problem and add a pattern for your site there, or make up a completely new section for your site. In any case, the recommended way is to disable only the prime suspect, reload the problem page, and only if the problem persists, disable more and more actions until you have identified the culprit. You may or may not want to turn the other actions on again. Remember to flush your browser's caches in between any such changes!
Alternately, if you are comfortable with a text editor, you can accomplish the same thing by editing the appropriate actions file. Probably the easiest way to deal with such problems when editing by hand is to add your site to a { fragile } section in user.action, which is an alias that turns off most "dangerous" actions, but is also likely to turn off more actions then needed, and thus lower your privacy and protection more than necessary,
Troubleshooting actions is discussed in more detail in the user-manual appendix. There is also an actions tutorial.
This is a quirk that effects the installation of Privoxy, in conjunction with Internet Explorer and Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may appear to be corrupted or invalid DUN settings, or passwords.
When setting up an NT based Windows system with Privoxy you may find that things do not seem to be doing what you expect. When you set your system up you will probably have set up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when logged in with administrator privileges. You will probably have made this DUN connection available to other accounts that you may have set-up on your system. E.g. Mum or Dad sets up the system and makes accounts suitably configured for the kids.
When setting up Privoxy in this environment you will have to alter the proxy set-up of Internet Explorer (IE) for the specific DUN connection on which you wish to use Privoxy. When you do this the ICS DUN set-up becomes user specific. In this instance you will see no difference if you change the DUN connection under the account used to set-up the connection. However when you do this from another user you will notice that the DUN connection changes to make available to "Me only". You will also find that you have to store the password under each different user!
The reason for this is that each user's set-up for IE is user specific. Each set-up DUN connection and each LAN connection in IE store the settings for each user individually. As such this enforces individual configurations rather than common ones. Hence the first time you use a DUN connection after re-booting your system it may not perform as you expect, and prompt you for the password. Just set and save the password again and all should be OK.
[Thanks to Ray Griffith for this submission.]
Privoxy cannot act as a proxy for FTP traffic, so do not configure your browser to use Privoxy as an FTP proxy. The same is true for any protocol other than HTTP or HTTPS.
Microsoft Internet Explorer (in versions like 5.1) respects system-wide network settings. In order to change the HTTP proxy, open System Preferences, and click on the Network icon. In the settings pane that comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox is checked and enter 127.0.0.1 in the entry field. Enter 8118 in the Port field. The next time you start IE, it should reflect these values.
Just dragging the Privoxy folder to the trash is not enough to delete it. Privoxy supplies an uninstall.command file that takes care of these details. Open the trash, drag the uninstall.command file out of the trash and double-click on it. You will be prompted for confirmation and the administration password.
The trash may still appear full after this command; emptying the trash from the desktop should make it appear empty again.
This is often the result of a webserver using PHP that mishandles the request Privoxy sends to not compress the content (a PHP bug).
In a default configuration, Privoxy requests all data be sent "uncompressed". This is required for the page filtering and other magic to work. In some rare cases, the browser and webserver miscommunicate and the result is a totally blank page. The suggested work around is to selectively turn off this feature for sites that exhibit such behavior. Example section for user.action:
# Make exceptions for ill-behaved sites:
#
{-prevent-compression}
.example.com |