We recently learned about a harmless but annoying bug in Firefox. Sometimes, even after a page and all included scripts have finished loading, you’ll see messages like “Transferring data from www.xyz.com ….” in the status bar., where xyz.com is the unfortunate site whose script was nice enough to let other scripts load ahead of it. Our <script> uses the defer attribute specifically so that it doesn’t cause any pileups during page load, and the end result is that it loads last and you might see “Transferring data from Sphere ..” in the Firefox status bar. Urgh. In fact, the page is done loading at this point. The message is a result of a bug (several related bugs, apparently).
A few users have contacted because they were concerned that our Sphere Related Content script was slowing down their page load. In all cases, it turned out to be this particular issue that gave them entirely the wrong impression (understandably so). Our widget script is actually VERY FAST to load. No processing happens during page load. We defer all of the magic for Sphere Related Content crunching until the widget is invoked by a user clicking on the Sphere Related Content link. As a result, our script does not hold up page loading. On my slow DSL connection, it hovers around 250ms.
Needless to say, those users who’ve run into this bug are miffed. And we’re miffed, too. But I’m sure the fine folks at Mozilla will have this one fixed soon. In the mean time, if you get this message consistently on your blog, check the load times using the excellent Tamper Data plugin and you’ll see that loads are completing and load times are pretty spiffy for the Sphere widget. Or you can change the load order of your scripts and make someone else look bad :-)