False banner recognition...

[RobinC]

I'm running Norton Personal Firewall and apache on WinXP (blah) and, (re)writing my website after a dead hd, found this strange effect -

If I include an image of say 400x68 pixels, I can view that in the site no problem, but if I set both WIDTH="400" and HEIGHT="68" (both mind you, one is alright) then norton filters out the whole IMG entry. I must admit that I've not come across this on other sites (I'm just glad it blocks so many adverts), but that's a nice looking size for the logo of my site ;-)

Obviously I'm going to get around it by changing the size of the logo very slightly, but I was wondering if recognising adverts by size is causing other people to change their image sizes, or even not include the sizes at all (though I like to keep it validated).

[Imaster]

I don't know whats with these damn firewalls, but my zonealarm pro always shows some banners and hides many.

[RobinC]

Well norton has a huge list of sites and what is/isn't adverts, it also seems to block certain sizes of image *only* when that image actually has the HTML tags for size set... So I can W3C validate, but I can't see the validation image myself - now is that an advert too?(well, took me all of 20 seconds to set it up to ignore my own site, but you know what i mean...) ;-)

[jeffb]

I noticed the same thing on Norton Internet Security (which includes Norton Personal Firewall). To find out exactly what Norton is blocking from your browser (and the browsers of any visitors who use Norton Personal Firewall at its default settings), try the following:

(Note: these directions assume that you are working with supervisor privileges on Norton and that Norton Personal Firewall uses the same interface as Norton Internet Security.)

1. Open Norton, click on Statistics, and then click the View Logs Button.

2. Click on Content Blocking and then check on each line of content that it has blocked.

3. In the Content Blocked details at the bottom of the screen, check the Data line. At the end of the line it will explain the reason that the item was blocked.

Make a list of reasons you find and you should have a pretty good idea of what banner sizes and file names you should avoid to keep Norton from blocking your banners and links.