Is there anything on a local network or desktop environment that could effect JScript execution?

I know this sounds odd. The JS on my project functions perfectly, except when the web site is accessed using computers at one specific company. To make things even more difficult, the JS fails only about 50% of the time when run from that company. The JS failure occurs with FireFox, Chrome, and IE.

I have tested this myself using FF and Chrome on a thumb drive. The browsers on my thumb always display my project site perfectly, except when run from a computer on said company's network where they fail at the same rate as the installed browsers.

My JS is using jQuery and making some Ajax ca开发者_如何转开发lls. The Ajax calls are where the failure is occurring. To diagnose the problem I created a logging function for my Ajax calls and recorded success and failure. Over a one month period, there were only a handful of failures (about 1%) from all access points other than this company. Oddly enough, the Ajax calls in the logging function are not failing.

There is nothing exotic there - Just Win XP SP3. I have never noticed any other unusual behavior from their network. The company is a division of a mega ISP and is on their corporate network.

Any other suggestions for troubleshooting would be welcome.

Maybe they have some data protection software installed (against data theft) they are not telling their employees about? It might account for the arbitrary (but notable) fail rate, rather than a firewall that would presumably block all traffic.

I would look in the company PC's task manager / process list and compare the list of running programs to a "normal" XP3 SP3 installation. Also, I would talk to the admins whether any protective measures are in place - with a big ISP, I imagine there might well be.

Just shooting in the dark, of course.

The intermittent failures were caused by the third-party product that was the target of the Ajax calls. It would, on occasion, simply not respond.

No explanation for the higher failure rate at the one location was ever found.