I'm active on a number of SE sites, so I keep a whole bunch of tabs open in Firefox looking for `(X) Newest Questions...` so I can click over and hopefully participate. At home (Firefox 25 on OS X 10.8.5) this (almost always) works perfectly, and if for some reason a site stopped updating, I just hit refresh and it works again. However, the story at work is different. I'm still using Firefox 25, but I'm on WinXP SP3. The following sites work fine: * [Ask Ubuntu](http://askubuntu.com/questions) * [Biology](http://biology.stackexchange.com/questions) * [Unix/Linux](http://unix.stackexchange.com/questions) * [Skeptics](http://skeptics.stackexchange.com/questions) * [MSO](https://meta.stackoverflow.com/questions) * and SO itself, with several tabs open watching various sets of tags However, [SuperUser](https://superuser.com/questions) and [Ask Different](http://apple.stackexchange.com/questions) are not working **at work**, and I can't figure out why. If I hit reload or <kbd>Shift</kbd>-reload the most recent questions come up, as they should, and *maybe* there will be the `X new questions with new activity` notification at the top of the page for perhaps 1-3 more questions, but then it stops, and I have to reload again to see the newest ones. The weird thing is that it doesn't happen at home, where those pages will happily refresh for days on end with no problems. Looking at the comments for [this question](https://meta.stackexchange.com/questions/199858/ajax-not-working-on-stack-overflow), I [went to websockettest.com](http://websocketstest.com/result/290503) and got green checks for everything. Additionally, I'm not behind a firewall (that it detected), but since it's a corporate network for a rather large-ish company (a few thousand on-site) and I've experienced filtering before (I can't download `.exe` files from some sites, but others work just fine?), there could potentially be something going on. However, it seems weird that it'd just affect these two sites, and not the whole SE network, so I really don't think that's the reason. Interestingly, I just refreshed and opened the newest post on SU, and after a few seconds I saw the `an edit has been made to this post` notification, and a little while later it got an upvote, so it's not like live refresh is completely broken on the site. However, during the next 35 minutes or so, eight new questions were posted, but only four were shown on the `X questions with new activity` notification. I do have Firebug installed (it's not active at the moment, too much overhead), so if you'd like me to look for anything special just let me know what to do. I really appreciate any help or suggestions, as this has been going on for months, and is really hindering my timely interaction with new questions on those sites.