Norton Internet Security woes

People who know me well will tell you that I have a deep-felt aversion to Norton Internet Security. I’ve previously had to look after a small network of home PCs that had it installed on some of them, and boy it was hell to look after.

At work on thursday I was contacted by a user of one of the web applications that I have developed with an interesting problem. She had just bought a new computer, and she was having trouble with the features of the site which used AJAX. Looking at my logs showed that none of the XmlHttpRequests which should have been being made were reaching the server.

So, what was the problem? She was using the same version of Firefox as she always had been, on the same Operating System, with the same ISP. The only logical explanation was that an overzealous firewall was blocking the requests before they left her PC. As I’m sure you’ve guessed by now, Norton Internet Security was the culprit.

Unfortunately, it seems like the solution to the problem is one that the user has to apply themselves. Thankfully, the gmail help pages contain a nice, easy to understand set of instructions for removing Norton Internet Security’s ability to block XmlHttpRequests. There are also instructions for users of other firewall software.

It’s quite possible that Norton Internet Security was mangling other JavaScript functionality, but the AJAX stuff was all that bit me on the arse this time. What I should note though is that the NOSCRIPT tag that I’d added to the page was not activated by the browser when NIS was doing its stuff, since JavaScript wasn’t actually disabled. So, a word to the wise there - don’t assume that just because you’ve made certain page functions available using judicious use of NOSCRIPT that all users will actually get to use them.

(No doubt the adverts below this entry will be trying to shove Norton Internet Security down your throats now. In case you haven’t guessed by now, I really don’t like the software, and I don’t think you should use it.)

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  1. by fowmow on July 6, 2006 12:21 PM

    Funny you should mention the horrible nature of NIS. Someone in alt.comp.lang.php ran into the same type of trouble when a certain script of his appeared to be acting up.

    I swore it had to be something in the script itself, never thinking that a firewall or other errant application could be modifying the output.

    I thought at the least NIS might say something to the user (within the output, markup source). Just goes to show, Norton is not as great as people tend to think.

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Neil Crosby now blogs at The Code Train and also runs, The Ten Word Review and Everything is Rubbish.